I have experienced similar problems, and from what I can tell, the following is going on:
1: JavaOP connects normally, and starts doing bot stuff
2: After a couple of minutes, JavaOP suddenly disconnects and is unable to reconnect (above error)
I couldn't figure out what was going on until it happened while I was playing StarCraft in the mean time - I suddenly got a "you have been disconnected from Battle.net" notice. Subsequent attempts to log in again resulted in "Connecting..." after which I was thrown back to the realm selection screen. Other realms work fine after this, but I can't get back on USEast. Short explanation: temporary IP ban on any realm I try to use JavaOP on.