Is the "Windows compatibility mode" an automatic feature"
It is turned on automatic making your Ubuntu experience a cross between windows XP and Linux. I was able to install 47 different windows software with no problems but uninstalling them is not easy since the installer sometimes complain about write accesss to missing drive. Ubuntu was passing the partition data the same way Linux does when uninstaller are being run (dev01/xxx and other similar drive info).
Maybe when they upgrade the support to the level of Vista/Windows 7, this issue will be removed. It must be on my side alone but almost all drivers that I am using for windows XP work on Ubuntu and the only one that complains was my Realtek built in sound.
I never upgraded the kernel since June last year but periodic patches are being applied.