I am using AfterEffects 7.0 on a Macbook Pro, with Snow Leopard on MAC OS X 10.6.3. AfterEffects will fail in the middle of a render and show an error message in the middle, saying that it "cannot create 720 x 480 image buffer - 7 :: 39." It will then let the rendered movie rest incomplete on the desktop, and sometimes, the application crashes all together. Sometimes, an error message appears saying therer is not enough memory to complete a movie, but it is completely unpredictable as to where in the render it will stop (one time, it didn't even last one frame!).
Steps to reproduce bug:
1. After editing, click Make Movie
2. Set the formats and specs, then press Render.
3. Wait a while for the bar to load, and wait for the error message to pop up.
Results: An incomplete video on the desktop, and a failed render in the application.
Expected results: A complete movie no the desktop.
I already sent Adobe a bug report with my email address attached, so hopefully that will solve some problems. It could simply be a matter of using an old version that can't handle the amount of memory or performance on this computer, yet I have been using this version for 5 years, and I have never had this problem before.
Here's a page that talks about avoiding the image buffer error in After Effects 7.0:
One of the main reasons that we made After Effects CS5 a 64-bit application was to avoid this error. Now After Effects has no difficulty with large frames, and it can use all of the RAM that you give it.
I know this is an old post but I just ran into this myself with AE7 and a Mac Pro, 10.6, and found the solution.
You just have to go into your AE preferences and set ram cache size to under 1GB of ram and it should work.
I know its probably not ideal since you have to work with such a limited amount of ram, but it works in a pinch.