Inconsistent emulated Wiimote behavior

[shazdeh]

There seems to be a strange bug with the emulated Wiimote feature (or probably it's my ignorance on how it should work), however this issue occurred on two separate PCs with Dolphin 5.0.
So, we were playing NSMB with 3 of the game pads set to "Emulated Wiimote", this was working fine. After about a week another wanted to join in, so I went to Controller Settings and enabled Emulated Wiimote for the 4th player, set it to Keyboard Mouse and used the Default button to fill-in the button mapping. Immediately after resuming the emulation, the controller for the first player broke, all A, B, 1, 2 buttons were doing just once thing (put the player into bubble), there were no more sprint or jump. I tried playing with different buttons, enabling different Extensions, none had any effect. This occurred on both PCs we tried (one with Windows 7, one using XP).
The inconsistent behavior however seems to go further than that, mainly that, after we loaded a saved state, the direction buttons for some players was reversed, we had to enable "Sideways Wiimote" to fix the direction, whereas it was working just before loading the saved state.
I apologize for the lengthy post, but I'd appreciate any help regarding the matter.
Dolphin rules!

[mbc07]

Keep in mind that unless you've a high end mechanical keyboard, most keyboards cannot handle a lot of simultaneous button presses and weird things happens when you try to do so. I'm guessing all four players are mapped to the keyboard?

[shazdeh]

No, just the one, as the fourth player. The other three are on separate gamepads.
BTW disabling the "Wiimote 4" (re-setting the option to None) had no effect also. Also tried re-starting the game from the beginning (as mentioned there were controller issues when trying to load a saved state) however that had no effect either.