I'm not sure if this is at all an issue, and it's rather small, but I felt it was worth reporting:

On any screen where you have a root tree displayed at the top, just below the top frame (i.e. Home -> [name]'s Profile), if you happen to put your cursor on the left end of the arrow or in a small space to the left of that arrow's left end (in the space between it and Home), it will strobe between the typical pointer and the hand icon.

Just something worth keeping in mind, I guess? I should also note that clicking during that accomplishes nothing, so it doesn't seem like it's actually linked to anything.

Not sure if this helps, but check to see if hardware acceleration is your issue. Pingaloca talks about it here:

http://na.leagueoflegends.com/board/...d.php?t=693781