Whether it is being reported twice really depends on looking at the status of the accounts that are being reported. If the accounts show as charged off , transferred or sold then this is a non active debt. The debt can be sold or transferred numerous times and that is why you may see the same account appear twice. Only one of these accounts should be an active debt and the other accounts should show a status that makes them inactive. If this is not the case then you can dispute the duplicate account.
Original creditors can be required to turn over the information relating to where they sold or transferred the loan. Some times they will voluntarily provide it.