I wouldn't think they could take money out of your account if they overpaid you...it is direct deposit, not an automatic withdrawal that you signed, so that's why they need to ask you for the money (they can't just reach in and take it, even if you had it).
I had my employer pay me 4 hours of overtime that I never worked, and they just corrected it on the next paycheck. They couldn't just withdraw that amount from my bank account. So, don't worry about them taking any money from your account (if you're now concerned whether to put any money into the account). I think Pirate is thinking of the automatic withdrawal authorizations, not the automatic deposit slips you fill out.
On a side note, Rick, are you a lawyer?? If so, I have a similar question, but it is about what you can do when your employer UNDERPAYS you and doesn't correct the mistake. Got any info for that??