I just got the BB Pearl 8100c (AT&T) yesterday morning. It is running OS v4.2.1.96 . My first question is is there a significant difference between the current version Im running and the and v4.2.1.109 upgrade offered in the above sticky?

Second question is when upgrading the phones OS will it completely reformat the phone erasing all my settings and data or do I not have to worry about backing everything up?

As you can tell this is my first smartphone

1. Minor bug fixes, its not a must, however It might improve the memory leak issue on your phone.

2. Part of the upgrade process includes taking backup of your phone and reapplying the backup after. In the middle it wipes the phone.
So yes, it wipes, but it backups. However it could fail, like everything else. But normally it goes fine

yea but what about 3rd party apps like JiveTalk etc.

They should back up and be restored as well. I believe there is a setting to do that.

Yes, they will, in most cases. You are wise to make your own backup first using Desktop Manager > Backup.

Also, reloading the OS will not always reload your license or registration number for some third-party applications. You would be wise to write down any license keys you know you may need upon reloading it.

3rd parties will backup and restore but as Sci-Tek pointed out there's always the small chance the load can fail. If that happens then you can eaisily restore your data via the backup but 3rd parties will be gone. I always do the following before every OS upgrade just in case:

http://www.blackberryforums.com/rim-...arty-apps.html