i was refering to EZEki3l's post where he says "/msg nick!user@host" as you also corrected. do you get an error if you do /msg nickserv? does your client have an ignore or blacklist where you must allow/deny certain hosts? do you have any client side scripts that could modify the functionality of the /msg command? you could try a /quote privmsg nickserv@services.network.tld help
to see if it is your client causing issues.
[Edited on 9/20/2006 by owine]