Interestingly enough, when I was messing with these settings and selected "update time" from the menu option, it set the date to 24 hrs ahead. Even changing it to Blackberry at first seemed work, but in powering it off and back on again, and updating the time, it revert back (forward really
to being a day ahead.
Also when sending messages via the Blackberry the header of the email still shows the GMT time as the creation date of the message and not the offset time, which is set correctly on the handheld. I have to believe the default time (and offset) is still being retrieved from the "network" and not the device itself, the date appears correctly. But it makes it tough to troubleshoot problems with timestamps and offsets incorrect.
Wonder if it's an OS issue as well, I know of several systems going to a new international date time format (IBM has with some of their software) but some the client software didn't know how to handle it, and it also messed up date and time stamps on mail clients.
Hope this gets fixes soon.