To clarify - when I split the clip it loses the audio completely. When I trim the clip it doesn't trim the audio along with it. In the QT program it looks like it does, but when I export it to play on Vimeo or YouTube, it turns out that, in fact the audio wasn't trimmed and the audio and vid don't sync. Boo!
I only have the basic quicktime version
the basic version ( QT player ) does not edit, you need to buy QuickTime Pro from here:
If you mean QT X read the help files on trimming clips it explains it well