O.K., as of being an offical TechNet member (who want's to touch me? :P), I have downloaded my Windows Vista RTM (build 6.0.6000). After doing some R&R (some means all night long) i did a driver update to ATi Catalyst 8.31.100 beta for Vista (owning a Radeon 9600XT). And I've installed Emperor - the only Westwood RTS I have missed to date, bought the game on Allegro.pl (polish eBay) like 6 months ago. Had the texture glitch (XP). Tried it now on Vista. Guess what. The game runs flawlessly!!! :D :D :D
