BUG - Abilities and skill shots aren't coming up first click.

its been going on for a good week now. ive tried 3 different keyboards but it only happens in game when the keys tend not to respond. if it is a skill shot it still makes the noise but the ability doent even come up. ive tried uninstalling and re the client but again nothing... id say 10% of the time my q,w,e,r and d,f dong go off. can anyone help please??? this is really affecting my game play. happens on smart cast or normal... help please!! thanks guys =)