Be glad she just called up. Psycho bitches are NO fun... I had an old girlfriend (who had a damn key to my place, call me a f'in idiot) come by at 2 AM loaded while I'm with another chick and try to open the door. Chain was on and she was banging on the door, screaming that I was an asshole and that my girl (who's my wife now) was a whore... Yada, yada, yada.
Scary the things you learn about people after you break up with them.