Summoner Spells not casting, despite proper binds.

Attached is a video. I finally caught it while streaming today.

It's been happening pretty frequently that a summoner spell is off cooldown but refuses to cast. I've noticed probably 4-5 times in the last few days with both smite and flash. Sometimes it works appropriately, sometimes it doesn't.

A description of what you see in the vod: Flash comes off of cooldown, I press D to cast, no other buttons pressed, and notice it starting to happen so I start smashing my d key, eventually hold down caps to talk on mumble, and while talking whatever the bug is releases and I flash.

Something's not right. Is anyone else experiencing this?

Edit: This forum is replacing the link to the vod with a link to my stream. Not sure how to fix it but

http://www.twitch. tv/kfrr/v/14849092 remove the space between (. tv) or click the link above the video.