upload the .ma file and we can take a look at it. If it works then you have mostly got a graphics driver problem. But it's hard to know for sure from just the description above.
Actually 72 frames @ 24frames/sec would be a three second clip. Except the default playback speed is "play every frame, free" so if you have a really fast machine it may be that it's playng at a much higher frame rate then 24 frames / sec.
Hover and right click over the time slider and set the playback speed to "real time" and see what that does.
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675
Last edited by ctbram; 16-09-2012 at 06:45 AM.