Megiddo, sounds like he's using the release version.
schnellbot, if you aren't using the SVN version of ULX and ULib, the menu's will most likely not work in multi.
We're almost out with a new release, but it may be a while.
For now, you can use your game console and it's autocomplete of ulx commands, along with "ulx help" for a list, for administrating your server.
SVN isn't overly difficult, but it does add some complexity to getting addons.
Several popular addons besides ours use SVN as their sole sharing method.
Once you've learned how to do it, perhaps you can try the latest ULX SVN.
Instructions are in the SVN topic