Mike, send a dispute letter to Palisades forcing them to give you the details of this account. As per the fdcpa laws, they must send you the details in writing before attempting further collections.
You need to send your dispute through certified mail with return receipt requested. Once the company receives your letter and thereby not respond to it, you have covered your base legally.
After verifying with the original creditor, if the company sends you the details and you agree to it, paying it off will improve your credit ratings.