That doesn't sound like a ban to me. They'd tell you if you tried to log on and you were banned, and being banned doesn't affect whether or not you can read the forums, as far as I know. Might be some sort of connectivity issue?

OOO finally banning for multiclient, eh?

Nooooooooo not Watermelon:((((((

I really doubt that this is a result of a ban, it sounds more like problems with NAT and/or firewall configuration problems.

Bans are against the player, not the knight, nor the account, nor the IP address. Once you have been banned, log on anywhere else will do two things. First, the login screen will tell you that you have been banned, why you have been banned, and if it is temporary, for how long you will be banned. Second, that new IP address/computer will be flag as being tainted by the use of a banned player and that they are now tied to your account.

Have you tried using ping to see if you can reach spiralknights.com? Have you used any other network diagnostic programs? Have you been messing with your router?

And, uh, as far as multi-clienting goes, ringers have explicitly stated that it is fine and have said so for many years. If you are banned while multi-clienting, it isn't because you were multi-clienting, but for something else you were doing. Oh, and note, that many bans don't happen until long after you stop doing whatever it was that objectionable. This is especially true if you were using some sort of cheating program, if OOO banned you immediately when they detected it, that would give the programmers clues about what caused the cheating program to be caught. Instead, OOO (at least in Puzzle Pirates) tends to make a sweep every few days and ban everyone who was caught cheating.