Hi Guys,
A message from the trenches....
Just a bit of a extra info that may or may not be useful. Once I dropped the dll into the GAC the problem I originally had disappeared but there was another 'funny' problem with references to the DevEx.GradientFormHeader. This was in an old and shakey part of the system that I was getting into again (reports related). Anyway, I presumed it was a new issue and carried on. Around this time I deleted something I shouldn't have and this caused its own set of issues and, simultaneously, my collegue was moving over to VS2008, SF 1.6.5. which again had its own problems and he became involved in my efforts to retried my deleted form and also had the GradientFormHeader problem.
The bottom line is that we came to think the source of all our problems was the Inherited UI dll but everything looked to be ok. The copy in the GAC had the same date/time as the copy downloaded from the SF web site. During this time we had both rebooted about a million times so that wasn't an issue. In the end I dug out gacutil.exe and did the install int the GAC using that but that made no difference and, for some reason, I rebooted and, what do you know, everything was fine....
I've no idea what's been going on but my recommendation for putting a dll into the GAC is:
Start the VS2008 command prompt: Start>VS2008>Tools>Command Prompt
Enter the command: gacutil /i "C:\Program Files\Common Files\MicroFour\StrataFrame\TheDLLToInstall"
Then reboot.
Cheers, Peter