You say the invoices are entered at a journal. Did you set the journal as a Debit item? So when you enter the invoice at the distribution positive numbers go to the revenue codes.
Then when you run TAXS to apply gst you select the AR code which is recorded as a negative on the journal (ie: plus $500 in Dist and Minus $500 to ar code)
Then when you block the 2 lines(actually only need to block the plus amt) and run PRTINVS, it should print the invoice and pick up the address from the notes view of the ar.
When you enter the inventory items sold in the distribution, what account code are you selecting? A revenue code or the inventory item?