Problem with A/P / Purchase Order entry and reports

I ran an income statement for one of my clients earlier today and noticed a major discrepancy on the report (in the COGS accounts). One of the Cogs accounts is off by over $160,000 (overstated). There are 3 months, and 4 transactions that affect this amount. Purchase orders/vendor invoices show $8.00, $45.01, $195.00, and $312.45 (for the purchases). The income statement (COGS ledger) shows the 4 transactions as $24,000, $16,800, $60,000, and $61,200 respectively.

I have run the data integrity tool to "fix" the errors, but it did not "fix" these 4 errors. I don't know what is causing the problem. The 4 items (customer invoices - all for the same customer) are all service items. I don't know if this helps.

I have gone in and changed the "account" on the purchase orders, as well as on the customer invoices, saved the changes, then gone back and put the correct accounts for the specific items. This did not change anything when running the same reports after making the changes (both times).

This is extremely frustrating to me, as I hate it when things are out of balance - especially when it is out of balance by over $160,000 for a client that does not do $50,000 in annual sales per year, and never has COGS of more than about $12,000 per year.

I have been on hold with Tech Support for over an hour already.