I dont have a wireless chuck, so i cant be 100% sure, but i can make some pretty educated guesses.
Your Wii has no fucking idea that you are using a non-standard nunchuck. Unless you are running SOFTWARE on your wii that "boots" the nunchuck, or Datel gives you some sort of boot disc or channel to install/play to make it work, then it is a HARDWARE ONLY device, and you're wii and wiimote cant tell the difference.
Now, since we know that neogamma is just trying to init your nunchuck like any other normal nunchuck, but the wired one works and the wireless one doesnt, lets take a look at the differences between the two. one is wired, the other isnt. ok, simple enough. one has the normal amount of delay when sending an electric signal from the wiimote to the chuck and back again, and the other one has to catch that signal, analyze it, convert it into a radio frequency, send it, receive it, decode it, and respond to it accordingly. Guess which one takes longer?
Try this, start neogamma without the chuck attached, and do whatever it is you are trying to do. once neogamma or yoru game or whatever is loaded and running, THEN plug in and turn on your nunchuck.
in essence, NeoGamma probably isnt waiting enough time for your Wiimote to initiate communications with the nunchuck, because it expects it to happen in a certain predictable amount of time, and the wireless one takes longer.
tl;dr
Neogamma cant tell the difference between wired/wirless nunchuck. Try starting yoru game without the nunchuck plugged in, then pluggin in and turning on the wireless nunchuck AFTER the game is running.