The Aged Trial Balance should tie to the AR control account when printed "Calculated as of" the period ending date. "Calculated as of" ignores transactions entered after the date selected. "Aged as of" includes all the transactions on file.

You'll likely have to inspect the transactions that are being sent to the Clearing account to see where the problem lies. One of your other accounts PO/Inventory accounts may be "pointing" at this GL account.