I never could get TellMe to register my GPS when I was running 4.2; maybe 1 out of 5 times I tried to link.
Now that Live Search uses the voice function, I have been using it. It's prettier at the very least (and I think they own TellMe now anyway).
I'm running 4.5.0.46 now, but if I found .48 I'd take one for the team and try it on my 8310 as well.
Just sayin'