Abrosia wouldn't do this if it was closed. Could you possibly have had two instances of the program manager running at one time? That could explain why you were buying things that weren't showing up in the buy window and why you got new items after you closed it (since another instance would still have been open).
Possibly. I know the account wasn't hacked or anything.. Who hacks an account and buys stuff and leaves it there without stealing the NPs. I just uninstalled it, I am going to reinstall today and see if that helps.