[AccessD] Windows 7

Hey All
I have an Access2003 program (MDE) used by a client, they have upgraded 
their machines to Windows 7  and now they get the dreaded  "The OpenForm 
action was cancelled" when they click the button on the main menu for 
one option (the others all work fine). The only thing this form has that 
the others don't is a CommonDialog control.  I haven't as yet had them 
check for missing references (the office doesn't open until 8AM, I may 
have to send them the MDB to check).  They startup the program with 
their version of Access2003.  In trying to research the cause of this 
problem,  I am seeing that  Access2003 can develop some problems when 
running under Windows 7. Have any of you run into other  problems?

Thanks
Tony