[Ekrimmer]

Here is what we've seen with our handfull of older (unpatchable) RIM Blackberries (957/5790):

Simply changing the time is not sufficient. A couple of factors are working against you - first being "network time" - if your Berry is set to Auto Update from the network the time will flip right back. This is also true if you didn't address the PIM synch settings in DM and turn off the time synch.

Even if you turn off any automatic synching and just set the time your appointments will be 1hr off from a correctly patched Outlook calendar/PC.

The solution here was to move everyone to Arizona. Ok, just change their timezone to AZ which is -7 GMT. They'll just have to move back to CA in April.

Of course not everyone will want to move to AZ - but you get the idea. Pick a timezone normally an hour later than you.