Using AP230 to tie to AP GL account

Our auditors wanted us to supply them with an Open Payables Report which tied to the AP GL account. When running the AP230, it did not tie to the GL. One reason I have determined is that invoices for which a messages exists appear on the AP230, but have not been posted to the GL yet. I need help thinking of why invoices would be posted to the GL, but not on the AP230. Any suggestions?

PS-I know the AP136 is the report that will tell us exactly what ties to the AP GL account but it does not give the invoice detail the auditors want.