The UI for Puzzle Quest on Wii seems to flake out a lot, selecting the wrong thing, not selecting where your pointer is. Is there anything that can help out with this, like upgrading to the new Wii-mote-plus? Or do you suggest something else?
If your pointer is over the thing you want to select, and it doesn't select that. It's a bug in the game.
My recommendation is to see which direction it is off and adjust accordingly (if it's always too far low and to the right, aim to the top left)
Using a Wii Motion Plus will not help, the game isn't built for receiving that data.
If it's that you're having trouble getting the cursor pointed at the right place, I'd recommend a recalibration in the Wii System options.