MF4 keeps screwing up the timing of an MP3 clip

[merk]

i wanted to use a portion of an mp3 clip as background music for the menu. When i hit the start mark point in movie factory, it totally messed up the timing of the clip.

Like i would tell it to start the clip at the 60 mark, but when i would hit play at 60 seconds, it would start playing from say 30 or 40 seconds into the clip.

Any idea whats going on there? I had to get around it by using another program to edit the mp3 file and then save it as a wav file and then import the wav file. Thats a bit of a pain in the rear...would be much quicker/easier if movie factory worked and edited the file.

Any ideas?