You should not edit h.264 natively in FCP, it is not an editing codec and it is fraught with problems. There are posts all over this forum every day about this if you search.
Because you’re using an ancient version of FCP with no ProRes support, your material should be transcoded to either AIC or DVCProHD for editing. Make certain that your audio is changed to 48khz during the transcode as well.
David Roth Weiss
Director/Editor/Colorist
David Weiss Productions, Inc.
Los Angeles
http://www.drwfilms.com
POST-PRODUCTION WITHOUT THE USUAL INSANITY ™
Colorist – UP IN THE AIR (electronic press kit) – nominated for six academy awards
A forum host of Creative COW’s Business & Marketing and Apple Final Cut Pro forums. Formerly host of the Apple Final Cut Basics, Indie Film & Documentary, and Film History & Appreciations forums.