sound and video do not coincide!

Hy folks,

I hope that somebody knows an answere to my question.

If I upload a video on my sansa e260, unfortunately the video and the sound do not coincide.

–> it is shortly decelerated. 

I tried to upload a short podcast from a german broadcast station and it worked. WHY?

Thx for help 

Wrong forum, dude/dudette.