Audio is too fast for vid

[Conformist]

Please forgive my profound ignorance. Although I do use ubuntu (simply because I hate windows and cant afford a mac) I am not very computer savvy. I have come across this program and it seems to be simple enough for my simple task. All I want to do is make a new video from a selection of a larger video that is in .mp4 format. When I remove the unwanted sections of the original video and save the file, all goes well. But when I replay the new video, the audio moves much faster than the video... Any suggestions?

Thank you so much... this is frustrating beyond belief, I have downloaded many programs and tried to do this simple task, some programs take FOREVER just to open the original vid. Avidemux loads it instantly and the selection process is easy and intuitive and saving is FAST but the audio simply moves out of synch... I really hope there is a simple solution that I am capable of understanding... Thanks again.

[Jan Gruuthuse]

What ubuntu version are you using? 32/64-bit? What version of avidemux are you using?
When using for both Video and Audio Output: Copy, this should not happen as the video and audio encoding is not changed.
When you replay the new video, is this in avidemux or with an other mediaplayer?
Can you upload a 5 second orignal source video and 5 second duration of video with the faster audio to rapidshare.com or similar web service? and provide a public available down link for these?