(sorry if someone said it i dont have time to read the whole thing)
I right click the shortcut i use for
EU and goto Advanced and check the box "Run as Administrator" and i havn't had any problems and thats with a crappy onboard vid card(geforce6150).
Eu doesn't run awesome but i can hunt and play.
I'll probably upgrade my card but overall i dont see what ppl are complaing about with vista i like it so far. and i've had it for almost a year now.