Critical Error Occured, when rendering timeline. Help!

I have windows vista, not the 64 bit version, 2 gigs of ram. Dual core processor. I have at least 250gb free on my hard drive. I have made several movies in premiere and haven't had a problem until now.

Just recently I started adding psds, jpgs, wmv's and a bunch of title slates. I was doing everything and rendering out with no problems. The other day I tried putting in another psd file (had transparent layers on it)I tried rendering the timeline and I got an error that said. Critical error occurred. Premiere Pro has stopped working and needs to shut down. So, I figured it was the transparent layers with the psd. So I convereted the files as sepearte layers to png files. Same error. It will bring up the render box for a split second then crash! So I dumped those files, the titles, the wmv, and I had one .mov file. Same error! What gives? I got back to a previous version of the file where I didn't add any of the extra stuff in and it renders out fine! Any help would be much appreciated.