I have a Tetris too :)
http://frank-duffner.de/noTWebApp_tetris.html
The touchy movement appears when you repeatedly hit a movement key instead of just holding the key down. I optimized for holding key down to have a fluid movement (no delay at the start of movement like i.e. in your Tetris). But it seems everybody is so used to this flash bug(?) that they keep hitting the buttons :(