I dont think anyone here has suggested HOP as being an IRCd command. I don't know of any IRCd that has ever had it as a server command.
The issue here is that mIRC isn't sending a specified channel key in the JOIN command when you're simply cycling a channel, only when you're hoping to a new channel. It's also sending the key in your PART message, which is a bit of a security breech. (Looks like a simple mistake in handling "$2-" parameters.)
- Raccoon
