Cordless Phones Reboot CM1150V when answered

I purchased a Netgear CM1150V for gigabit speed and it is the only one that has voice.  The problem (1 of many) is the main base stand-alone phone is connected into the CM1150V.  The Panasonic stand-alone phone works fine.  It has three cordless phones placed throughout the house.  When an incoming call is answered by one of the cordless phones the call is not answered and continues to ring on the initiator side.  The CM1150V modem then reboots. modem then reboots.  I cannot figure out this issue.  There have been a few other posts but no answers on the solution