I have a fresh instal of vista 64bit with adobe premire cs4. On certain projects opened from previous cs3, the project will open playbak, edit, but will not save. The save window just hangs w the yellow bar never going across. Anyone seen this problem? Other projects operate fine. Would this mean I must have a corupt file somewhere in the mix?

I opened the problem project on another newer "i7" computer, and it opens fine but does the exact same problem; It wont save. So it must not be hardware related. It must be something about the project itself or CS4.
The same project opens in CS3 and saves properly. Ive formally been working on it in CS3.) and it will open in CS4 but will not save. From this information we can conclude that something about this project must have problems. So what can cause a bad project?
Could it be a corrupt media file?
Could it be the mixing of different codecs? ( AVI, M2T, MPEG, MJPEG, XDCAM )
Any body have ideas what i could try?

Specs - Computer 1.
CPU = intel Quad core Q6600
MB = Gigabyte GA-X38-DQ6
RAM = 8GB Corsair
GPU = Nvidia 9800GT
Windows Vista 64bit home

Specs - Computer 2.
CPU = intel i7 920
MB = Gigabyte GA-EX58-UD5
RAM = 6GB Corsair
GPU = Nvidia 8800GT
Windows Vista 64bit home

I figured it out, after only a week.
It was a missing codec that was causing the problem. I had not installed Blackmagic Intensity codecs for MJPEG video files that were in the project. I forgot i captured a few shots with blackmagic intensity and the new Vista 64 bit instalation had never had the blackmagic card in it or the drivers installed, so the project didnt know what the files were and it crashed. Wow, glad i solved this problem. Cant believe i didn't realize this now.