User Program Scan Glitch MT2000 ?

[RadioSouth]

I have a MT2000 A-7 set up for user programmable scan. I have 6 zones set up with a total of 98 personalities. Zones 1-5 all OK I'm getting the usual 15 scan capable channels per zone (on those zones that are using all 16 channels). On my last zone (#6) the radio is only allowing 6 channels at a time to accept user program scan. I can take a zone member off the scan list and substitute another but it won't allow more than a total of 6 for this last zone at a time. Any ideas ?
While on the subject anyone know if there's a limit on the number of scan channels temporarily deleted thru nuisance delete ?