Hmm, thank you for this idea.
It didn't work on my sites.

I think I will drop the complete JoomSEF solution, since we don't get help for this 404 problem.
JoomSEF worked very good for long time on my sites.... what a pitty.

Thanx to the programmers.

I also have this problem on different sites.
Only a downgrade to 1.5.1 helped :-(

Hope this problem will be fixed soon, since there are a lot of threads around here...
Thanx for this great component!

--Joomlaz