As furkey bro said, taking courses outside of your major is not a big deal.  The counsellor is full of sh*t. However, I am pretty sure that you can be in big trouble if your I-20 has already expired on 5-31-2011. I think the grace period is no more than 90 days to get another I-20.  Dont waste time, contact your Intl Advisor or lawyer if needed.