Well if you have the 8100 Pearl
http://www.blackberryforums.com/gene...dafone-de.html
that's the update you need.
But first make sure you know which version of the Pearl you need.
I'm not too sure how firmware for different phone version works but to be safe you have to check.
To check you can go to :
Options
About
and it should say Blackberry 81xx (xx being the number) :o