MSP430F67791A RTC issue

We are using MSP430F67791A microcontroller for our HT meter project used the internal RTC .

We observe RTC is not increment on below conditions:

1. After vibration test RTC is drifted 40 minutes back  from present time
2. When we make the  meter on –off (Clapper and file scratch test) for several times RTC  is lagging by almost one second per on off
3. During climatic test the date has not incremented at all. Generally climatic test runs for 10 to12 days, we observed that after completion of test the date observed was of day 1 only so the date is not incremented

Hence we conclude during on condition the RTC is working properly but in Off condition RTC is not behaving properly in some meters.

RTC battery is connected to AUXVCC3 pin3 of micro.

Please suggest the solution for this issue. What has to be take care in Hardware or firmware or Any condition for Auxvcc3 during on off of the suuply.