you may tried this, but try the following incase you missed a step...
btw, are they alkaline batteries?
Do this on the Wii's channel screen or shortly after launching the game. It may not work if you are into the game's sub menus.
- For the first time:
- open the small Flash Drive door on front of the Wii.
- remove the battery cover on the back of the remote.
- hit the red button found inside the Wii's door then the red button on inside the Remotes battery compartment.
- watch blue flashing lights on Remote.
- Temp synch or rotating remotes?
- simply hit the home button on a remote
- point to Remote Menu at the bottom of the screen
- it highlights blue when you point to it
- click on reconnect remotes
- follow onscreen instructions