Good Afternoon All

This is my first post here so I hope I am in the right forum. I am using DVD MovieFactory 2 SE that I got with my DVD-R burner. I am currently trying to drag and drop MPEG, AVI, ASF files and so on to make them into a DVD and for the most part I can get them to work fine but on a good portion of the clips that I have when I try to import them I come up with a "file format mismatch" error. Is this as simple as a bad file name or is it someting more complex and will I be able to have these files converted into DVD's

Thanks for the help

Redeemer462