What does a data integrity check show? I suspect the problem originated from an orphaned batch file from Accpac Plus.

Can you print and purge the batch status report?

If the problem was an individual adjustment batch file, then that might be easy - look for files starting with ARA and then 4 digits for the batch number. If the problem is with the batch control file then it's trickier as batch control is a set of files that covers all of adjustments, invoices and cash.