Quicktime Freezes giving an extra long timeline

I'm opening up some .movs that are about 2 minutes long in Quicktime Pro and the last frame freezes while the timeline continues to play for another 15 minutes or so.

When I import them into Premiere CS4 they do the same thing. The clip freezes on the last frame shot while the timeline continues to play for awhile.

I took my mac to the Apple store where they tried one of my clips in FCP and the clip length matched the video length. They suggested to reinstall my OS - but I wanted to check with you guys first.

I also thought when this first happened that the video would freeze while the audio played on.

Has anyone ever seen this or has a clue to fix it?

Quicktime 7.6.4
Mac OS 10.5.8

Thanks!
Sean
I'm also going to post this in the Adobe Premiere Forum in case I'm in the wrong place.