Try printing an AP "listing", rather than an "aging". It is possible that you have an invoice with a future date, which would not show up on the AP Aging.
 
In case this is not the answer--make sure that no one is entering A/P invoices, and that everything is posted before running the aging.
 
If you still have an out-of-balance, print the G/L transactions for your A/P Account, and make sure that no general journal entries have been posted to that account. If there are journal entries, they need to be reversed and posted to another (correct) account.
 
If all else fails, a journal entry will be necessary to correct the "Out-of-Balance" condition.
 
Darlene Hattox
Admyr Wireline, Inc.