Which versions of MySQL support it?

4.0.2 up does ... if I understand the manual correctly.
But as there is one report from 4.0.24 where it is not working, maybe only 4.1.X does support this Syntax?

Bob, could you test if it's working for you?

I'm running 4.0.24-Standard, but I will install it and give it a shot. ;)

Thanks :)
I guess editing a User will not work, but I am interested if it does add Usergroup Members as Mods (when you add the Usergroup as Mod) on this Version

Ok, installed fine and I just added the administrators as the mod group to a forum. Is that what you needed to know or do you need me to check something else while I am playing? ;)

And when I check the forum it shows each admin in the mods drop down listing.

Great, so this part is working - only the multi-table delete causing Problem then :)

What do I need to do to test that part of it to make sure it just isn't a fluke on another system?

Just Edit a User

Sorry, got the same error on that one. :(