If you've not installed ULib and ULX right, then that's the only reason I can think of that means not even "ulx" would not work.
ULX by itself shouldn't say 'unknown command', it should return an error stating it needs more information, and to try ulx help.
Did you extract the ULib and ULX files to your
server addons folder.
See the ULib_readme.txt and ulx_readme.txt within the latest versions downloaded from
www.ulyssesmod.netI believe both give paths of what the structure should look like.
Then see this -
http://forums.ulyssesmod.net/index.php/topic,383.0.htmlStep 1 even mentions the readme files, but doesn't state where they are (I'll go modify that right now)