I thought that this suggestion by JohnnyRoy shouldn't get buried in
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=676393&Replies=19This Post [/link]:
Here's an idea if you really do need to do deep zooming... Delete everything in the project except the 8MP images and save it as a new name. Then render just the 8MP images out as video. Then add the video back to your original project. This will eliminate those large images from the equation. Like I said... large image support works great in on Vista 64 with 8GB of memory... not so good with XP32 and 2GB of memory limit.
I can't see doing that until I'm certain that I'm done with ALL editing and thus won't need to move the images around again, but once set, I could see this eliminating some annoying rendering glitches.