Sometimes I get a broken background in Chrome. I do not get this error with any other browser.
This is the simple CSS line responsible for the background color of b
Everybody has said your code is fine, and you know it works on other browsers without problems. So it's time to drop the science and just try stuff :)
Try putting the background color IN the body tag itself instead of/as-well-as in the CSS. Maybe insist again (redudantly) in Javascript. At some point, Chrome will have to place the background as you want it every time. Might be a timing-interpreting issue...
[Should any of this work, of course, you can toggle it on the server-side so the funny code only shows up in Chrome. And in a few months, when Chrome has changed and the problem disappears... well, worry about that later.]