My husband and I both got booted with Error 318 whenever we were in heavy combat and used interrupt or block. I tried remapping the interrupt function to the 8 key . Tried it out yesterday in a battle and was not booted out at all. I held the 8 key down for quite a while several times and also pressed it repeatedly and never got booted out with the 318 error. In fact there were no problems at all.
NOTE: Prior to this I did a bug report every time I got Error 318, as has my husband.