Imported mp4

I've a important question!!

Recently I uploaded a mp4 file and a mp3 file (external sound) for a music video. The problem is that the mp4 file sudenly changes its speed. Its faster then the external sound... If I just watch the mp4 file in Quiktime it is the right speed... Tried it on an other mac with final cut, but the same problem happend... Does somebody knows whats the problem and how to fix??

Thanks

Are you trying to sync the files? What are the audio sample rates of the two files? Use WAV or AIFF rather than mp3 if you can.

Like Tom said, with audio, sync issues are pretty much always a sample rate problem. For working with video, all files need an audio sample rate of 48kHz, period. And I'll back him up on using WAV or AIFF instead of MP3 for quality audio.