Money missing

i been away for about a week, and when i came back i found out im missing around 400 in gold and i don't know what could have happened? I haven't told anyone my password or opened my acount anywhere else, so i don't know whats going on. A couple of times i found my bag in a different order or an object missing but i thought it could be a bug.
I've changed my password now, but i want to know if theres a way i can tell if someone is signing in my account, thanks!
It has not allowed me to choose categories in the support, so I could not send the problem.

http://forum.warmane.com/showthread.php?t=412515