can't save movie when I use a custom Profile

When I try to save a movie I get a message that it cannot
save to specific location, check there is enough disc space.... blablabla...

This error happens ONLY if I use a custom profile (made with Window Movie
Profile Editor). MM2 works fine if I save in DV-AVI or HQ NTSC.

I already read in the papajohn website 'Can't Save A Movie'.
My movie is very simple since it contains only one 1min sequence.
I have enough HD and RAM available (the Peak is about 1/4th of the Limit
commit charge!).

I can't find how to solve this stupid bug!

Do you have any idea?

Please help.
Thx