PA_ADDITION_FLAG = N instead of T for IC invoice lines in AP in R12

We've created IC invoices and interfaced them to AP and AR.  My question is related to the pa_addition_flag values on the distributions in AP.  In 11i, the processed ITEM distributions have a pa_addition_flag value of T while the TAX distributions have a value of Y.  In R12, the processed ITEM distributions have a value of N, the REC_TAX distributions have a value of E, and the NONREC_TAX distributions have a value of Z.
I am running a query to look for any PA eligible distributions (validated and posted) that should flow when the interface processes are run from AP to PA.  My query looks for distributions with a pa_addition_flag of N, so the ITEM distributions are showing up as eligible.  Since these are the lines from the IC invoices, they are not eligible and should not (and do not) flow to PA when we run the interface process.