While I've been having no problems with connecting to games, I HAVE been having identical problems with the chat overlay. Same error message as one displayed in your first image.
ERROR: Closing Link: MyName[~MyName@IP address] (Excess Flood)
I've actually been recieving exactly the same problem when dealing with the chat system in "The Political Machine '08 Express", so I'm thinking it is probably a personal system/firewall conflict with the Impulse Reactor, rather than Demigod itself. If it is of any consequence, I am running XP service pack 3, and I'm hiding behind a "Norton Internet Security 2005" firewall.