I had a long look around for bugs related to this issue and this was the closest. It does
state 7975's but you never know
CSCtq86175 - User settings and call history may be lost for 7975 phone if it is reset
Symptom:User settings and call histories may be lost for 7975 phone if it is reset or if firmware is upgraded. User settings includes attributes such as phone background image, ring tone etc. Call history includes missed calls, received calls, placed calls.Conditions:Two scenarios could lead to the problem:(1) Firmware upgradeor(2) Phone resetFor both the above scenarios, the problem occurs extremely intermittently.Workaround:There is no known workaround.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...