Eck! nero video decoder!
 

nero 6 has installed some video decoder, its overriding all others and guess what, its god damn awful.

I can't figure out where it is. Can anyone point me in the right direction so that i can unregister it?

Search for NeVideo.ax and rename it and it´s gone.
Do not know if that make problems for Nero when you are burning (S)VCD but try.
If it does just rename them again.
You could also edit it in the registry (regedit).
Search for Nero Video Decoder and you will find it.
Make small changes (so you can undo it in any case of problem) in the registry and just experiment.
Do not have time to do it myself right know... (on my way to see LOTR ROTK :D ) but maybe later.

Good luck!!