After the daylight saving time (DST) patch is applied or Cisco CallManager is upgraded to the latest engineering special (ES), the 7961 IP phone with a side car 7914 that has a shared line with a second 7960 phone is stuck in Requesting Template and does not register with Cisco CallManager when the phone is reset.
The issue is documented in Cisco bug ID CSCsi32167.
In order to workaround this issue, complete these steps:
Delete the shared line on the side car in order for the phones to register.
Once the phone registers, recreate the Directory Number (DN) again.
In order to fix the issue, upgrade to one these versions: