The CSV export follows PO Edit List's logic. If the PO and line items are printed, then they will be exported to CSV. So the question is why do the canceled entries show up if you only choose “U R P"? The reason for this is because the PO Status “U R P” selection is based on the PO Header status. That is to say, even if a PO has some canceled line items, if the PO header still has a status -- say “P” --  then that PO will still be printed. If the PO is printed, then the associated line items are also printed even if they are canceled.

The selection of PO status based on PO header is old logic from the Macola(R) days, and we are not sure if we can change it to the way you want without causing problems for other users. Especially there's no such thing as "U" (Unreleased) and "R" (Released) status at the line item level; in other words, the PO status is for the header only.  As for your situation, you just need to know that some canceled PO line items may still show up in the CSV. Since you can filter out those canceled line items in spreadsheet once the CSV is created, we think this is not a critical issue.