I couldn't get the XT Dock to work -- it would switch tom docking mode, but wouldn;t always charge the battery -- I returned the dock.
Were you connected to your computer via USB? I found that if the computer was asleep when I plugged my phone into the dock that it would not receive power. Had to have the computer on and awake and then plug the phone into the dock. It would keep charging if the computer went to sleep after already being connected.
The XT dock is working perfect for me!