OK - there is a big thread on this already.
It is v4.2.0.69 - the package is called .84 in order to confuse everyone.
You will not find any information on what it fixes since release notes are very hard to come by. And none for this.
I have done the upgrade.
Here is the original thread..
http://www.blackberryforums.com/gene..._cingular.html
Closing this one.