I'm using the ChatZilla plugin to Firefox to connect to an IRC channel at work. I only see messages from the time I connect forward. Is that an ironclad rule of IRC, or can I see the last hour of messages somehow?
Only if you are the channel operator, or if you have an IRC bot hang around to log the conversation. You might try asking the channel host or other members for their copies of the logs.
Also, since most IRC are user-hosted, there may be a custom /history <#> command you can use. It will only work if the channel mod has installed an extended script kit to include the /history command.