Screen flash freezing client

So, I've had a problem that's really been making me angry about the new client. Sometimes I'll get a screen flicker, and when I do, the whole visuals part of the client freezes. I can still click on things as if I could see them, but nothing on my screen changes visually. This never happened in the old client and it causes a lot of stress when I'm trying to get into a game, then I end up missing a Queue pop or can't select a champ and get put on that bullshit waiting list. Fix this crap! Thanks.