70-200 f2.8 USM IS II - Slow focus... HELP!!!!

I really like my 70-200 on fixed and slow objects but at times it's very slow to focus or it does not focus at all.  This happens in lower lght and at close distances most... BUT.... It's also slow on BIRDS and Fast moving people.

Perhaps it's me.  I'm using a 7D. Any advice on optimal setting for fast moving objest with this beautiful lens?

Here's what it does GREAT!  I need to get up to speed on fast moving objects with this lens!!