I have a CM version 6.1.2.1000-13 with 7911 firmware version SCCP11.8-3-4SR1S.

I have a remote location where I have put the majority of model 7911 phones. This is my first remote location on this cluster that has the majority of 7911 phones. I have a growing handful of phones at this location that after a short period of time stop audibly ringing. You can see on the LCD that a call is coming in but it no longer rings or lights up display. Also when this problem is happening the answer button is greyed out as well as when I go to select ring type the play button is greyed out.

A reset of the phone usually brings it back to life but after a while reverts back to having the problem. Anyone seen this issue or know of any bugs out there.

My gut feeling was to upgrade the firmware. I have installed the latest firmware thru the OS Admin and it updated my device defaults but for some reason the phones will not upgrade. They just register real quick to the same firmware version. I am remotely logging in so the best I could do is try and reset the the web interface, that did not work, so I reset the POE switchport but that did not make the phone upgrade either.

Anyone have any ideas??