First national collection Bureau contacted about a Paid account some online reports say they are a scam?

I paid my account even though it was past due to a lawyer representing the first bank of Delaware back in 2010 I haven't heard from them since. Now in June of 2011 I have got a letter stating i now owe these new people for the same debt the First National Collection bureau How is this possible? looking online some reports claim this is a scam of sorts they buy old or near the statue of limitation accounts and press for money has anybody else dealt with this person?