After Editing Video & Audio not in Sync in the AVI file....HELP!

I capture home movies from Digicam using WMM2 in AVI format, edit it using same software,. I save it after edit as an AVI file. I have checked this AVI file before encoding and the Audio & Video are not in sync, 3/4 into the movie. Does anyone have any suggestions. I have checked the captured file and it seems fine. I have tried the process several times now with same result. Previously I had successfully done 2 home movies like that, all is well with them. The original on this movie is also ok. Please help.