Office 2007 Ultimate will not install on Windows 7 Ultimate

I've this problem twice now on two different computers. When I try to install
Office 2007 Ulitmate on Windows 7 Ultimate, it lets me put in the CD key,
then it lets me customize my install (run all on this computer), but when it
goes to the actual install, I get back an error "Office source engine has
stopped working". No code or anything. It does give the option to either
close the program or check for an onlin solution. I've let check for an
online solution, but as usual with this option, nothing came back. I can
install Office 2007 Ultimate on an XP machine (haven't tried it on Vista, but
I think it works). And other versions of Office will install on the Windows 7
Ultime. It's the combo of Office 2007 Ultimate and Windows 7 Ultimate
(haven't tried other versions of Windows 7, but would assume the same
problem) that does not work. I've updated .NET 3.5 SP1 thinking that might be
an issue, but that didn't help either. I believe this to be a Win 7 issue.
Any assistance would be appreciated. BTW, there are nor were any other
versions of Office and this was a fresh install of Windows 7.

Thx,
Mark.