Well, i where fideling around perhaps a bit to much, and ended up with a bunch of users without a username.
The result where that I couldn't delete them, since the link in the userlist is dependant of the user actualy having a username.
Don't worry, this is not a bug in WebGUI in itself, but rather a effect of my poor Perl knowledge while developing a NIS authorization plugin.

This small patch "fakes" a userid in this list if the user has none.

I gues that this patch is mostly for developers and perhaps not good for the "mainbranch".