I just install the new OS Snow Leopard and the new release of Final Cut 3 (Upgrade).
The following problems appear:
During a "crawl text" play the text has a noise like flickering after rendering.
If I create a crawl text in MOTION and exporting it in FC3 and I render it in FC3 the crawl text working well.
What were you using to make the crawl? There have been a few posts about a bug in the Boris text tool not making interlaced crawls in FCS3. Search the forum as I think there may be a link to a Boris software upgrade.