HAD A PROBLEM WITH A CREDIT CARD INVOICE.  VOIDED THE AP CHECK, AND REPRINTED CHECK.  NOW MY AP AGING SHOWS THE FIRST VOIDED AMOUNT, BUT IT IS NOT REFLECTED ON THE GL ACCT.  THE AGING SHOULD BE ZERO, THUS MATCHING MY GL BALANCE.  I CAN'T FIGURE THIS ONE OUT.  I REVIEWED MY GL TRANSACTIONS, AND EVERYTHING LOOKS OKAY.  HOW CAN I CLEAR THIS OFF MY AP AGING TO GET THE BALANCE EQUAL TO MY GL BALANCE?

You need to look at both the BKAPINVT and BKAPCHKH files in Maintain Database to figure out where the extrra entry on the Aging is coming from.  Aging looks at invoices in BKAPINVT and applies payments from BKAPCHKH up through the Aging date.

To fix the error 11, you need to go to UT-A, program MDBFXREG.  Accept the path, then exit DBA and come back in.  As for the file extensions, you need to know what the extension of your company code is.  The B is the Default Company, the B99 is the sample company that comes with DBA and any other extensions are companies you have created.  If you click File - Change Company and look at the list of companies available, the company code (without the "B") is shown in brackets after the name.  The company you are currently in is not displayed on the list so if you are in your company, whatever one is not listed is the file set you want.
 
As for the data, find an invoice that has been paid normally and look at both the BKAPINVT and BKAPCHKH records and see how the data is coordinated.  Then look at the records for the items you are having trouble with and see if you can identofy the problem.