Call Parking Problem

My company has taken over IT for a new client and they have Asterisk on their server. Currently they have 5 Snom320 phones that work great. I purchased two more Snom320’s which also work great. However, when the user recieves a call on the new phones, puts it on hold, another user should be able to pick up the handset, dial 701check and pick up the call. This works on all phone but the new ones. The new users can dial the 701check and pick up parked calls but the old users cant pick up calls the new users have parked. Does this make any sense? I need help!!! Thanks!