Ok, I have managed to find one DEFINITE cause of this error 10053. It is very unlikely that it is any of YOUR causes but still, it triggers the abort.

Code:
On *:OP:*:{  
  :doploop
  mode $chan -ooo $snick($chan)
  goto doploop
}


Whack that into your mIRC editor and join an empty channel so you have ops. Fire up a clone (in the same mIRC instance, get it to join that channel and op it. Both server connections will terminate straight away (at least, it does with me (mIRC 6.03 and Win2k)). And no, I'm not gonna explain WHY I wrote this particular piece of code :tongue: