If your BlackBerry changes time automatically when you travel across time zones, it can affect applications like Outlook that hold your Calendar information. Your whole schedule can get thrown off. To prevent this from happening, you have to perform the following steps:
1. From the main menu, press Menu.
2. Open the Clock application.
3. Press Menu.
4. Select Options.
5. Select Set Time.
6. Set Date/Time Source to Off.
You will have to manually set the time on your BlackBerry Storm now, but it will keep your appointments from getting jacked.