Anybody else who trades through Penson been having problems lately? In the last week, I have been locked out of my account because of a margin call when there was more than enough cash to cover. I never come close to full margin because when I do I always close down to leave a nice cushion. Second, they didn't have my option excersises from this past weekend in my position on Monday. Then today, they double my position. Maybe, I'll get another margin call.