Messenger 7 Cor****ate login

Operating System: Mac OS X 10.4 (Tiger)
Processor: intel

I'm trying to log in to my cor****ate account on Messenger 7. I diligently
copied the network settings from Messenger 6.0.3, which is working fine.
They don't work on Messenger 7 – "Not connected to the network" etc. Same
for the Personal account.

Disabled firewall, dumped preferences, not trying to run both 6 and 7 at
the same time.

What gives?