I have two Pitbull X3 chargers, both excellent. I too hate the noises, so will investigate disabling the speaker - good idea!
I think my software versions are 2.9 and 3.1, but I e-mailed CE and they said there was no discernable difference between the two. They did offer to update my old one though if I sent it in, and inferred it would be free.
It is a great charger, apart from the noises, and I think it is one reason my cells seem to last longer. Best charger I have owned.