We have just purchased some CP-7811-K9 phones but they are not registering. I have set up the phone profile and added a DN but it won't register. I've installed the latest phone software (cmterm-78xx.12-1-1SR-4.k3.cop). The screes just shows the message Registration in progress and occasionally shows "Error Mismatch" When I look at the Phone Information shows the Active Load: sip78xx.11-5-1SR1-1 and the message Last Upgrade: Upgrade Failed.
Any advice would be appreciated.