That's Vista for ya. I had a similar issue when I disabled all the bells and whistles in the Vista GUI, performance went to crap in some programs, I just read this to my boyfriend and we both agree that it could be a lot of things (personally I think Maya is being underpowered hence the crashing). Don't know your configuration, is it off the shelf or built from scratch. Go in and instead of using those power and gui presets, manually change/disable them so you know EXACTLY whats being changed. Tweak your startup options, there's probably a lot of crap running that you don't need.