One of the export bugs still remains in the newest beta release 1.0.90:
When I try to export to QuickTime from a clip which is not the first one (by setting IN and OUT) I still get a freeze frame movie of a single frame in the first clip. There's no such problems with other output formats.
Dual Quad Core Mac Pro 3.2GHz
8 GB RAM
ATI Radeon HD 2600