Well I just now found this out:
My own IP was banned in the ShoutCast DNAS. I just did a server RESTART and now my IP is NOT banned any longer. All is well again. Can anyone make any sense of this??
It means your IP is not in the ban list permanently, that's why is no longer banned after restart.
Most likely your DNAS it's been hacked, I have seen DNAS been hacked to show custom messages, and even redirect to other sites. I would not be surprised if it could be hacked this way too.
All of this cases are restored after a simple restart, which means the hack can only affect the running process memory.
Try switching to ICecast, or Shoutcast 2.0.