A problem with Movie Maker

I used Movie Maker on my XP machine without any problems at all. On my vista
machine I have problems with some, but not all movies. The problem is when
I'm trying to cut in exactly the right place, the preview freezes. I can
still save the project but I have to restart Movie Maker in order to be able
to preview any changes. This is rather tedious and I gave up on one movie
and went to my XP machine. The preview is much less likely to freeze if I go
back to the beginning every time I preview, but this is time consuming.
Thinking this may have been to do with system resources, I disabled as many
background processes as I could (who needs antivirus anyway?) including
visual effects. I have 3 GB and use 4 GB ready boost, but it doesn't seem to
make any difference to the problem. Any tips please, including alternative
software. I've now making a two-minute video and I've got this audio track
that I want to cut really cleanly, towards the end of the movie. Such a pain
when I've got to keep in running for 100 seconds in order to preview the
cut. And if I expand the timeline it tends to freeze.

So, please, has anyone got any tips. Any help would be appreciated.

Paul