SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D
                                  Rule 13d-101

                   Under the Securities Exchange Act of 1934
                              (Amendment No. __)*

                       INTEGRATED SECURITY SYSTEMS, INC.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                   45812J101
--------------------------------------------------------------------------------
                                 (CUSIP Number)

                               Russell Cleveland
                 8080 N. Central Expressway, Suite 210, LB-59
                               Dallas, TX 75206
                                (214) 891-8294

--------------------------------------------------------------------------------
            (Name, Address and Telephone Number of Person Authorized
                     to Receive Notices and Communications)

                                   12/31/2006
--------------------------------------------------------------------------------
            (Date of Event which Requires Filing of this Statement)

--------------------------------------------------------------------------------
      If the filing person has previously filed a statement on Schedule 13G to
report the acquisition that is the subject of this Schedule 13D, and is filing
this schedule because of ss. 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check
the following box. |_|

      NOTE: Schedules filed in paper format shall include a signed original and
five copies of the schedule, including all exhibits. See Rule 13d-7 for other
parties to whom copies are to be sent.

      * The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which
would alter disclosures provided in a prior cover page.

      The information required on the remainder of this cover page shall not be
deemed to be "filed" for the purpose of section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).

Page 1 of 4 Pages


CUSIP No. 45812J101
--------------------------------------------------------------------------------
(1) Names and I.R.S. Identification Nos.(entities only) of reporting persons.

    RENAISSANCE CAPITAL GROWTH & INCOME FUND III, INC.
    75-2533518
--------------------------------------------------------------------------------
(2) Check the appropriate box if a member of a group (see instructions)   (a)|_|
                                                                          (b)|_|
--------------------------------------------------------------------------------
(3) SEC use only.

--------------------------------------------------------------------------------
(4) Source of funds (see instructions).

    WC
--------------------------------------------------------------------------------
(5) Check if disclosure of legal proceedings is required pursuant to Items   |_|
    2(d) or 2(e).
--------------------------------------------------------------------------------
(6) Citizenship or place of organization.

    TEXAS
--------------------------------------------------------------------------------
Number of shares beneficially owned by each reporting person with:

    (7) Sole voting power:
        33,326,780

    (8) Shared voting power:
        N/A

    (9) Sole dispositive power:
        33,326,780

    (10) Shared dispositive power:
         N/A

--------------------------------------------------------------------------------
(11) Aggregate amount beneficially owned by each reporting person.

     33,326,780 (1)
--------------------------------------------------------------------------------
(12) Check if the aggregate amount in Row (11) excludes certain shares       |_|
     (see instructions).
--------------------------------------------------------------------------------
(13) Percent of class represented by amount in Row (11).

     33.4%
--------------------------------------------------------------------------------
(14) Type of reporting person (see instructions).

     IV
--------------------------------------------------------------------------------

----------
(1)     Consists of 32,362,716 shares of common stock, 187,500 shares of common
        stock issuable upon conversion of 7,500 shares of Series D Preferred
        Stock, out-of-the-money warrants to purchase 764,706 shares of common
        stock and out-of-the-money options to purchase 11,858 shares of common
        stock.

Page 2 of 4 Pages


Item 1. Security and Issuer.

           This statement relates to the Common Stock ("Common Shares") of
           Integrated Security Systems, Inc. (the "Company" or "ISSI").  The
           principal executive offices of the Company are located at 8200
           Springwood Dr. Suite 230
           Irving, TX 75063.


Item 2. Identity and Background.

          (a) Renaissance Capital Growth & Income Fund III, Inc. ("RENN III")

          (b) 8080 N. Central Expressway, Suite 210, LB-59, Dallas, Texas
              75206.


          (c) RENN III is a business  development  company regulated under
              the Investment Company Act of 1940, as amended.

          (d) N/A

          (e) N/A

          (f) Texas

Item 3. Source and Amount of Funds or Other Consideration.

           The total amount of funds required by RENN III to acquire the
           securities reported herein was $6,174,024, a portion of which was
           interest due from outstanding debt securities of ISSI where common
           stock was issued instead.  The source of such funds was the working
           capital of RENN III.  The RENN III options were assigned to RENN III
           by Mr. Russell Cleveland, the President of RENN III, who received
           them as compensation for service on the Company's Board of Directors.

Item 4. Purpose of Transaction.

           RENN III acquired the Common Shares herein in the ordinary  course
           of  business  for  investment purposes.  Russell Cleveland, president
           of RENN III serves on the Board of Directors of the Company.

           Persons associated with RENN III may participate in discussions  with
           management or third  parties in which they may suggest or take a
           position with  respect to potential  changes in the  operations,
           management or capital structure of the Company as a means of
           enhancing shareholder value.  Such suggestions or positions may
           relate to one or more of the transactions specified
           in clauses (a) through (j) of Item 4 of this Schedule 13D form.

           Associates of RENN III continue to assess the Company's business,
           financial condition, results of operations and prospects, general
           economic conditions, the securities  markets in general and those for
           the Company's securities  in particular, other developments and
           investment  opportunities, as well as RENN III's investment
           objectives.  Depending on such assessments, RENN III may acquire
           additional  securities or may determine to sell or otherwise dispose
           of some or all of its holding of securities.

           Other than as described above, RENN III does not have any present
           plans or proposals which relate to or would
           result in any transaction, change, or event specified in clauses (a)
           through (j) of Item 4 of this Schedule 13D.

Item 5. Interest in Securities of the Issuer.

          (a) RENN III holds an aggregate of 33,326,780 shares of the Common
              Stock of the Company which is 33.4% of the outstanding shares of
              the Company.  This consists of 32,362,716 shares of common stock,
              187,500 shares of common stock issuable upon conversion of 7,500
              shares of Series D Preferred Stock, out-of-the-money warrants to
              purchase 764,706 shares of common stock and out-of-the-money
              options to purchase 11,858 shares of common stock.

          (b) RENN III has voting and dispositive power over 33,326,780
              shares of the Common Stock of the Company.

          (c) During the past 60 days, ISSI issued 361,945 shares of common
              stock to RENN III in lieu of interest due on outstanding debt
              securities.

          (d) None

          (e) N/A

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to
        Securities of the Issuer.

           N/A

Item 7. Material to be Filed as Exhibits.

           N/A

Page 3 of 4 Pages


After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

                                      Renaissance Capital Growth & Income Fund
                                      III, Inc.

Date: 06/29/2007                      /s/ Russell Cleveland
                                      Name:  Russell Cleveland
                                      Title: President


The original statement shall be signed by each person on whose behalf the
statement is filed or his authorized representative. If the statement is signed
on behalf of a person by his authorized representative (other than an executive
officer or general partner of the filing person), evidence of the
representative's authority to sign on behalf of such person shall be filed with
the statement: Provided, however, That a power of attorney for this purpose
which is already on file with the Commission may be incorporated by reference.
The name and any title of each person who signs the statement shall be typed or
printed beneath his signature.

ATTENTION--Intentional misstatements or omissions of fact constitute Federal
criminal violations (See 18 U.S.C. 1001). (Secs. 13(d), 13(g), 14(d), 23, 48
Stat. 894, 895, 901; sec. 8, 49 Stat. 1379; sec. 203(a), 49 Stat. 704; sec. 10,
78 Stat. 88a; Secs. 2, 3, 82 Stat. 454, 455; secs. 1, 2, 3-5, 84 Stat. 1497;
sec. 18, 89 Stat. 155; secs. 202, 203, 91 Stat. 1494, 1498, 1499; 15 U.S.C.
78m(d), 78m(g), 78n(d), 78w) [44 FR 2145, Jan. 9, 1979; 44 FR 11751, Mar. 2,
1979; 44 FR 70340, Dec. 6, 1979; 47 FR 11466, Mar. 16, 1982; 61 FR 49959, Sept.
24, 1996; 62 FR 35340, July 1, 1997; 63 FR 2867, Jan. 16, 1998; 63 FR 15287,
Mar. 31, 1998]

Page 4 of 4 Pages