I e noticed this over the last few days so thought I'd post here I case any odd noticed similar. I think windows either A) drains power faster than the power cord can supply and as such cuts into the battery slowly over hours. Or B) is unable to charge the battery because it's drawing so much power just to run. I play civ 5 gods and kings on my win7 partition. 3-4 times now over last few days I've noticed the cable light suddenly turn to charge and notice to my surprise my battery was charging up from say 89% or so. Yet it would stay charging for HOURS and never get past 93-94 or so. Then I'd boot back into OSX and charging would be done in like 5 mins. Now this is weird. But it begs the question did I accidentally knock the power cord slightly lose on my leg and notice realize until later and hence it's charging up. But still doesn't explain the fact win7 can't seem to charge properly. Or I didn't knock the power cord lose and win7 is slowly eating into my battery over hours. Can't really say but i do tend to notice when my cord is not properly attached as the green light is fairly conspicuous.