My video I have made is 1 minute and 10 seconds long. I have done a RAM preview but I am only able to get 38 seconds of video time where there is actually sound. For some reason the whole video is cut off after 38 seconds.
When doing RAM Previews, AE uses all the RAM available to it... so you don't have enough RAM to preview the whole comp.
Since the audio ends before the video, your processors can't keep up with the images AE is trying to play back from RAM. Reduce the comp window size to 50 %, and the comp window resolution to half. If it still doesn't play back in real time, reduce resolution to quarter.
Don't get all bent out of shape because you have to do that. Every AE person I know uses the work area for previews. Unless you happen to know somebody with access to a code-cracking supercomputer at the National Security Agency, your situation is no different.
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA