Payment Terms on PO different than Vendor profile

Anyone else run into this -- I've got at least 2 vendors where each time we enter a Purchase order for them the payment terms default to, say, Net 60 -- however the terms set up in their vendor profile is, say, Net 30... This doesn't happen for all vendors just a couple. I can't see anywhere on the PO form where the terms date is reflected or provided as an option. I expect the purchase order to reflect the same terms that are on the vendor's profile, but because that isn't happening the invoices are constantly being scheduled for