i have the same problem. i just recently downloaded the game (1 hour ago) and a problem has arisin. everytime i connect to a server and select a character and team i receive either a 'kicked' command from over-zealous admins :S
and then when i try to connect to a different server, right when steam has finished pre-chaching resources i receive this error
"the half life launcher has expeirenced an unknown error"
"we are sorry for any inconvenience this may have caused you"
and its frustrating me to no end because i would really like to play this game... alas, i will keep trying.