in town lag when multi boxing

hey I've been trying to figure out why I get a ton of lag on 1 char or sometimes all when one or more characters are in town. Any thoughts or idea as to what the cause of this? I had no problem multi boxing when I first started doing multi boxing couple months later I get this crazy lag. No hardware changes with my computer too so I was thinking might be some windowerfunctions

If it's started happening as of this month, then I believe it's due to the Halloween event. I'm pretty sure it has caused severe enough problems for even console players that SE had to provide a temp work around of some kind that they posted about, but I forget the details. However if your problem started before the event or if it continues after the event goes away then I'm clueless. =/

not really been few months buts its getting worse so I asking if anyone knew my video carr is just fine for the game has the power for it