Are you getting an error message? I've tried on 4 different installations, from my development version to a live 1.2.0 upgraded from 1.1.8, to a straight 1.2.0 installation, and all seem to be working. If you're under mod_perl, try restarting it. Also check that your registration number (Setup -> Miscellaneous) is set properly.
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com