When the ball hits the paddle from the side and the user tries to move the paddle in the same direction where the ball is placed, checks seem to fail and the paddle is fragmented.
When a sound is being emitted, if the user pauses the game and later tries to resume it the game won't start again. This happens because sound is not set to 0 when the KEY2 button is pressed and it will stick to 1, indeed in the timer 2 handler (which is disabled during pause) the assignment of 0 to sound will not occur.