I recently put together a new system running Vista 64 and an ATI 4870 video card. Now I was getting lots of crashes in After Effects. After much research I found out there is an issue with the ATI open gl drivers but that others had found stability using the DNA drivers http://www.donotargue.com/. The driver did fix my AE problems however-
Now I get an error on opening PI saying the "atioglxx.dll is either not designed to run on Windows or it contains an error. Try installing the program using the original media ..." For whatever it's worth the drivers are supposedly for Vista 64 so I'm not sure what to do at this point.