Q/N Mates are HARD (at least for me!)

Watch Mr. Ed gallop around the board because I didn't know what I was doing! This was a victory, but an inefficient one:

You did well.  It was fun watching your cavalryman chase th king. 

A Queen and Knight by themselves probably aren't going to force checkmate on a King that's running around in the middle of the board. Basically what you want to do is win a bunch of pawns (like you ended up doing), then try to promote a pawn (which you also attempted), while always looking out for simplification oppurtunities (ex. 38.Qxd6+ followed by trading Queens, then pushing a pawn and trading the Knight for the a-pawn.)

Thank you. *Blush* P.S. The most satisfying thing about this game is that it was concluded with both of our queens still on the board. ;)