Thanks for the heads-up to un-check both boxes; I was able to change the settings.
As we have it, Line 1 is SP1, Line 2 is SP2, Line 3 is SP3.
Lines 1, 2, & 3 all ring for incoming on phone 1. When I transfer calls manually (*72) on the phone, lines 1 and 2 transfer correctly to my cellphone, but not line 3. I also, am still having difficulty with any of the lines forwarding when busy, even though I set the ObiExpert settings like you described above.