After effects CS5.5 not playing any composition RAM preview at 25 fps, instead its playing from 13 to 24 fps
Sorry to hear that. Change the comp window's resolution to Half and the size to 50%. You should be good then. That's assuming, of course, that you're actually doing a proper RAM Preview and not just writing that you are. If you're hitting the space bar, you're wrong. If you're hitting zero on the numeric keypad, you're right.