My mistake, I thought you were using 8x24. It looks like you may have 0x32. If so, go back to Ringing Services and press show. It should then say Ringing Groups, press next until it says 'Sched:Night' then press show. Next until Line Settings, show. Enter the line number having trouble, press show. It should say Ringing Grp:001 (or 002, 003 - just write the number down) Press Heading until you get back to Sched:Night, press back until you get to Ringing Groups, press show. Enter the ringing group number that you wrote down. Press the soft key under 'Scan' Keep pressing it to show all sets that are assigned to ring in this group. If the four sets in question are not listed, you can press find, enter the set number, then press change so the display says 'assigned'
Hope this helps. Let me know.
Chris