For some strange reason, all the videos converted by TMPGEnc end-up mute. No audio at all!!

Also, after the video ends this message comes up everytime:
KillTimer(hwnd,(UINT_PTR) hwnd
At line 3494 of e:\dx8\multimedia\dshow\filters\image\video\dvideo .cpp
Continue? (Cancel to debug)

If I answer 'Yes", nothing happens, if I press "Cancel" it says "Wmplayer performed an illegal operation"

Any clues? Thanks