Can't play movies on computer

Last year my friend and I each bought a Sanyo VPC-HD700 in Las Vegas. We used it there and when we got back to her home (in USA) we both downloaded onto her comp. We were very pleased with the results. Two month later she came to stay with me in the UK. When she tried to play on my comp they played like a series of still pictures, all jerky, although they played very well on the camera. When she got back to USA she sent it back, they didn't find anything wrong with it but she still can't play them on the comp, but they play perfectly on TV. Now the same thing has happened to mine. The older movies I took still play alright so I know it isn't the comp at fault. I was wondering if anyone else has one of these cameras and had the same problem, if so how they resolved it.

I had a similar problem with an older kodak digital camera. The soultion I used was to use the media player in my nokia pc suite to view the movies, then use roxio creative suite to convert the ones i wanted to keep to mpeg.
I hope this helps