Clearly it's attempting to use the ports of the previous server for the 2nd connection, which are not available for Absurd-IRC.
I don't see how you can make that conclusion from the log snippet you provided.
I also can't reproduce this bug with my list. Can you describe in detail exactly what you're doing? Perhaps provide part or all of your servers.ini in some form (or if its the default just say so).
My test:
I have a group "net" with two servers: test1:6667 and test2:6666
I type /server net and it cycles through the servers properly.
