no. scrap all that. i finally figured it out. because it just happened. in my case anyway. my CTRL button was sticking and i was hitting ESC. CTRL+ESC=game minimizing. when ever i have my inventory up or anything i always hit ESC to close it. so anyway. stoner moment.
problem fixed
Pressing alt and enter also does this, in case you have your item highlighting on atl.
http://eu.battle.net/d3/en/profile/Twoflower-2131/hero/47336841