sorry for my bad englisch but i try my best…
I had the same problem, i cannot encode to mp3 ogg or wma with installed encoder lame and or wm 9 codec package. Maby, it is not the best tip you ever have heard, but my problems have been away since i formated my PC and installed OS again. The only thing that have changed at the new installation was the installing of Service Pack 2 from Microsoft.
Cannot give a better tip, but now it works without any kind of problems.
best wisches Kai