Actually the block has been possibly giving me a few problems. I say possibly because it could just be me, or my keyboard.
Sometimes, like you describe, after I block I can't swoop to get distance and if the guy that I blocked is right in front of me I can't hit him. I try tapping the right mouse button, try holding it down, try moving around while doing both of thoes. Then *bam* he's gotten tired of me acting like a fool and I get hit across the map.
Another thing with the block is that I can only use it if I'm not holding down any other keys or buttons, and even then I sometimes have to hit it twice to actually block. A guy is swooping at me, I drop my beam, let up on all the keys and bottons, wait half a second, then hit the block key only to stand there and do nothing. And I don't have time left to hit the key a second time.
I don't use my "Q" button all that often but it seems to work fine outside of the game.
*shrugs*