I am trying to find the newest OS I can install on my curve. I have found a couple of newer ones, but they are not cooperating with me. I did change mine from 4.3 to 184.108.40.206 at the end of last year.
Hopefully the new upgrade will help with the calls. Sometimes, I people can't understand what I am saying on the phone. If I resay it, then it may be clear. They ask what did I do, and I say nothing different.
The latest software update for the Curve is v4.5 according to the blackberry website. I would not recommend using another website to update your phone because there are updates out there that have not been tested or approved by RIM and could cause your phone to run poorly.
Some have it some dont. I have it randomly but the benefit of the browser and OS being faster is worth it. Since we will never see the 5.0 OS on our devices and its doubtful VZ will approve any more OS's for our phone at all with the Tour, Storm 2 and the 8530 taking the place of the current roster. I would say .160 will be it for the curve.