Indicator for spells will randomly disappear or cancel.

Ever since the latest patch I have been unable to play champions that require skill shots because about 25% of the time i will hit the corresponding (lets say "Q") the indicator to show the spell will only show up about 1/4th of the time when I press the Q key. Sometimes I may have to press the button as many as three times before the indicator will show which as you can imagine in a game that is as time sensitive as league it can be very debilitating. I realize i could switch to smartcast, but I like using shift for smart cast institutionally. This problem only appeared after the latest patch and re installing league did not fix the problem. This problem does not affect me in other MOBAs or games so i know its not hardware side.

Thanks for your help, Chris