Last night I tried to play Trauma Center: New Blood in Co-op mode with a friend. I've done this before with no problems - each time I've had to use One Time sync to connect the 2nd remote while in the game. But last night, I could not get any of my 4 remotes to connect as the 2nd controller. All of them connected fine as the 1st controller, and battery power was at least 75% for each one.
If I exited the game and went back to the main Wii screen, all 4 remotes connected just fine...I'd just hit a button on them and a single light would light up on each one accordingly. I know the remotes aren't broken and that they are "hard-synced" to my console. The only time there was a problem was when I tried to use One Time Mode for a 2nd controller while Trauma Center was loaded. I don't know why there was such a problem with that 2nd controller slot...especially since it was working fine this way just a week before.
There are two things that were different this time. One, I normally play the Wii at my own place where there is WiFi, but this time I brought my Wii to a friend's and did not connect it to WiFi there. Two, I have started playing Link's Crossbow Training. As far as I know, neither of these changes should have affected the connection of a 2nd remote. Any suggestions?