I know this sounds silly, but be sure that you have fresh batteries in each Wiimote and that you have them in the right way.
Whenever you start up your Wii, the first Wiimote that you press a button on becomes controller number 1 and then subsequent Wiimotes are added in the order a button is pushed on them. SO, if you are thinking that you have remote 1 because that was the one that was remote 1 last night, it doesn't necessarily mean that it is so. Be sure that whenever you activate a Wiimote, the lights flash - 4 lights flashing mean strong battery, 1 light flashing means replace; when flashing stops, the number LED that is lit from the left denotes which remote you have. Make sure that is the same Wiimote that you select a game with, and make sure that is the one you press A&B together with to start the game.
If it doesn't work, shut everything down and start up using the other Wiimote. If that DOES work, then it could mean that your other Wiimote is not syncronized with the console. See the directions in your Wii manual on syncronizing additional Wiimotes (they're called Wii Remote by Nintendo) to your console.
Good luck. If all the above fails, you may want to go to www.nintendo.com
and request customer service.