When I created a FreeBSD VM, installed Apache/PHP, etc. on it and then installed the UBB from scratch, I didn't have a problem.
One thing I noticed though was that when doing the install on FreeBSD, it populated the path and URL boxes, whereas on the Windows installs, I had to enter them.
I hope this may have been an issue with Windows XP, as opposed to IIS/Windows in general. The disposable FreeBSD virtual machine is ok to test with, but our production server that will be upgraded is running on Windows Server 2003 with IIS.
Tim
