Same here. It has never worked, as far as I can remember. Depending on where the setting happens to be left at, my battery runs out in just a few hours, or I cannot use it in the car.
Aside: I switched to an original Droid from an iPhone 3G, then onto a G2X. My next phone is going to be an iPhone -- and I'm not coming back to Android until Google figures things out. Android is nice, but I hate being out of date after a couple of months, and having to install unsupported, hacky, half-broken user-built ROMs to stay current with the state-of-the-art functionality.