If you say N to Print Non Released Lines then you can't change the choice about backorders. So the real problem is skipping the question about printing non-released lines - which I can get to and change.
Double check the modified date of T6SOC.RUN - the one in the latest patch file is 6/23/05. Download from
www.istechsupport.com/dl/620patch.zip if you have an older one.