imTOO video conversion problem

I'm stuck with getting imTOO to convert from avi to mp4. It used to work fine but has recently stopped converting video - it only converts audio - for reasons I don't know. I have installed/upgraded many things on my PC (XP) since the last time it worked so - who knows. Anyway, to try to get it working again, I uninstalled codecs DivX, ffdshow and AviSynth. I then reinstalled as follows:

DivX V6.8
imToo 3.1.53.0620b (re-installed over the top of an existing installation as I was concerned about losing my registration data if I remeove imTOO)
AviSynth V2.57
ffdshow rev 2020 20080622
Windows Media Player 11
QuickTime 7.50

After this, no change - it still only converts audio. When I look at the file info (View->Show File Information) it only shows me a summary and audio section

Any suggestions please?

Are U sure that you use the right player?
If no problem with the player, check the file after loading and choose Properties, we need the info. there to find out what the problem is.
Thank you!