A scam company by the name of DROA (Domain Registry Of America) is currently very busy sending out FAKE invoices to owners of .COM, .BIZ etc. domains .. I've already received two this week, however DON'T EVER PAY THESE INVOICES!! - It's a scam and you'll end up loosing all your money.
Peter Larsen from GratisDNS have put together a great information page - be sure to check it out: http://www.droa.info/