I haven’t made any changes to the site for quite a while, but I do know Chrome has recently gone over to hardware acceleration, about 3 weeks ago I think.
I know Chrome has changed because all of a sudden when starting it up it was clocking my graphics card up to full speed, ATI Trey Tools was detecting it as a game, I have since made an Exclusion for Chrome in Trey Tools, it is at the top of the list in the attached image. FF and IE were hardware accelerated quite a while back and their exceptions are also on the list.
So my money is on a Chrome hardware acceleration issue, I’m not saying that chrome is to blame, it could be that I need to tweak the sites CSS file for the new Chrome.
It could also be a graphics card driver problem, might be worth up-dating to the latest driver for your card.