Hm. I just found a post of Jan here:
http://ez.no/developer/ez_publish_3/forum/general/how_to_disable_some_module_
But it looks as you already found that out yourself ;)
Did you clear the .ini cache? (Or all caches)? Close and open your browser (even if you are not logged in, your rules probably are only checked once every session).
I have now located the problem.
The system is running 3.2.3. If I replace the file /kernel/form/process.php with the same file from version 322 everything works fine.
I dont know what is wrong with the file? maybe a bug?