My small ambition is to delete chunks of inferior footage from mp4 video files transferred from Sanyo camera, using avidemux, mandriva09.1 and KDE.
The cutting process in avidemux is delightfully obvious, but the audio is not simply cut with the video - in the edited file, the audio has been sped up and finishes well before the video.
I found a tutorial, but as usual, some things in tute are not visible in my reality, and some things in my reality are not shown on the tute.

I've clicked on the 'Build Audio Map' as suggested, and it may be building, but no signal;

And the Saving process(es) is/ are ambiguous.it seems I must change the name, it doesn't like overwriting a file which is open in avidemux.which is the only one I would ever want to overwrite.

Either way, when I save it, it prompts me to make a smart copy, which I do, or don't, as the experiments proceed, and then also is the matter of setting a value between 4 and 30 or so for another unknown.
I saw floss avidemux manual, but it doesn't concern itself with basic operations.
Any suggestions about where to find simple, basic, unambiguous info?

'Tis but a small ambition, only to cut bits out of a video file

I don't have objection to buying software, it is after all the result of people's time and work, and I don't mind contributing to 'free' software also for same reason.
I just wanna cut the videos.