I mean, jump then stab on the way down, not downthrust. When you are coming down from the jump, they lower their sheild and you stab at that exact moment. Also, are we talking about the same knights? I'm really talking about Iron Knuckles, but I figured I'd just use the same term everyone else was using.

I also played with the Wii Remote only.

I didn't realize Iron Knuckles (forgot that was their name) always lowered their shield.  I'll have to try that out.

I used the Wii Remote with LoZ yesterday and I didn't like it.  The D-pad was a bit too small (although responsive) and my thumb was wandering around too much.   The Wii Remote jacket was getting in the way so it might be better with it off.  Otherwise I will try the Wavebird (I think its supported) before I buy a classic controller.