I will change the chat client soon... we won't be using mibbit anymore. I hear too many issues with it. I had an operserv exception list for mibbit hosts, its main client IP and widget IP, I had throttle exceptions, I had it in the allow block, etc. It worked for months then suddenly it doesn't work anymore, and it's not worth the fuss of emailing mibbit to put us on their list. Not enough of the users on SLR (from other communities) use mibbit to worry about it.
PJIRC used to be more than satisfactory; it's what I used when I started on this site and first became a chat op. So we can use it again.