* Note that I am speaking as a member of Windfyre's staff, and in no affiliation with ZFGC or #zfgc.
A mode was set on the channel to prevent non-registered users from joining the 5 major channels on the network, since an active botnet was found on the server. A global message was sent to all users (which Ryan must have missed) that stated the reason for it. The channel was in this mode for approximately a half hour, (until the bots were banned and the threat was past) after which it was removed and things went on as usual.
It isn't very hard to register your nickname, though you were using another user's nickname, and that is technically against the rules. You may register it when it drops, as we discussed in #Services. That was really the right place to go for any help with network issues, as you are likely to get a fast response from the people helping to run the network there.
To reiterate, the channel does NOT require registration to chat except in the case of an emergency. It is wise however, to register your nickname so that other users cannot take it from you and/or impersonate you. Additionally, you cannot recieve permanent status in any channel without it :p