Two instances of same account on at once.
 

I am housesitting at my mom's. She loves to enter sweepstakes and download anything that the internet tells her to. Her computer is in bad condition with a lot of Spyware. I got rid of a lot of it but it's still a mess. It only plays slightly better than EQ actually did in 1999... Maybe even worse. Whenever I camp I crash out of the game. So after this happened twice I decided, since everything takes so long, to just keep 3 or 4 instances of the log in screen up at once so I can get back in faster when I need to change characters. So after I camped I started logging back and was ready to spam the you currently have an active character - thing, till it went away. But it never told me I had an active character. Anyway when I finally got to character select I noticed I was still on character select on the other instance of EQ. It was the same account. I never logged in either of them to see if I could because I thought maybe it would flag me as being cheating or something. I'm not sure if it would have let me log them both in, or either. After about an hour I left the house. I came back a few hours later and one had crashed. IDK if this is a known issue or what. IDK if it's just something only my mom's computer can do because it's such a hot mess, but I figured I'd let you know.

Ive had this happen swapping out accounts too quickly 1 time. Somewhere along the way one of the accounts registers as a different account in the system and acts like it has a ip exemption.