Exhibit 10.04

INSIGNIA SOLUTIONS PLC

41300 Christy Street
Fremont, CA 94538
Telephone: 510-360-3700
Facsimile: 510-360-3701

June 30, 2005

Fusion Capital Fund II, LLC

222 Merchandise Mart Plaza
Suite 9-112
Chicago, Illinois 60654

Re: Securities Subscription Agreement Dated as of February 10, 2005

Gentlemen:

This letter is being delivered to confirm our understanding with respect to
certain issues under that certain Securities Subscription Agreement, dated as of
February 10, 2005 (the “Subscription Agreement”), by and between INSIGNIA
SOLUTIONS PLC, a company incorporated under the laws of England and Wales (the
“Company”) and FUSION CAPITAL FUND II, LLC (“Fusion”), pursuant to which the
Company has agreed to issue to Fusion the Ordinary Shares, 20 pence nominal
value per share, of the Company represented by American Depository Shares
(“ADSs”) in an amount up to Twelve Million Dollars ($12,000,000) in accordance
with the terms of the Subscription Agreement. All capitalized terms used in this
letter that are not defined in this letter shall have the meanings set forth in
the Subscription Agreement.

Fusion and the Company hereby agree that the Company shall have until August 15,
2005 to file the registration statement referenced in Section 4(a) and that the
June 30, 2005 date referred to in Section 11 shall be deemed to be September 30,
2005. The provisions set forth in Section 11 of the Subscription Agreement are
hereby incorporated by reference herein.

  INSIGNIA SOLUTIONS PLC

  By:  /s/ Mark McMillan    

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  Name: Mark McMillan   Title: Chief Executive Officer     FUSION CAPITAL
FUND II, LLC   BY: FUSION CAPITAL PARTNERS, LLC   BY: SGM HOLDINGS CORP.

  By:  /s/ Steven G. Martin    

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  Name: Steven G. Martin   Title: President