We've had some reports about customers "losing" contacts after the GMS
2 upgrade in conjunction with deleting and re-adding the accounts on
the device to force a switch to the 12.1 ActiveSync protocol. Before
you do such a drastic step in recreating the account please ensure that
all your address books are properly configured for sync into GW. If
any contact is created on the device in a book that is not synchronized
into GroupWise the contacts will be lost when deleting the account as
some devices do not retain local contacts when deleting an email

Also most devices don't have any issue while continuing to use AS 2.5.
Unless you plan to use an MDM solution which requires AS 12.1 we
recommend using AS 12.1 either by rebooting the device or recreating
the local account. However most devices will switch after while
without any additional steps. The server cannot influence the device
behavior regarding when and how they switch. The only devices we
recommend switching to AS 12.1 are Blackberry 10.x devices because the
Blackberry AS 2.5 implementation has a few bugs that are solved by
Blackberry using 12.1.

Your world is on the move. http://www.novell.com/mobility/
We know what your world looks like. http://www.novell.com/yourworld/