URGENT ! IT MAKE CONCERNE YOU!!

I made film by windows movie maker. Everything was OK but when I opend after 30 days this *.MSWMM file all my work (30 hours) with movie maker drop in water. I have found that neither avi file can't produce sound. Everything looks like that avi film has audio sound speedy . If I have sound with 50 sec it will sound like in 10 sec ( very fast) with big noise

I made test and opened imported avi file. If I mark this file in collection and start play everything will be OK....but if I drop this avi file to TIMELINE sound will be speedy with noise. Does anyone know solution for this error?