I just got an Intel Mini Mac (512Mb of RAM) and Final Cut Studio (Universal version) with FCP 5.1. The Canvas (the right side screen that plays back the timeline) won't play set to "Safe RT" (it says "Not Rendered") and stutters and stops when set to "Unlimited RT" for just regular DV footage from the tutorial. Is the solution more RAM, or playing off the internal disc rather than a firewie hard drive.
Anybody that's got it working, please help me with your advice