CSS: Background invades content when zoom in (IE9)

I'm trying to figure out the reason for a weird behaviour in the browser. The thing is when you start zooming in the webpage, suddenly the background comes in and invade all the content.

I've been walking around this but without results.

Of course the problem is only using IE. It works as expected on the rest of browsers.

Here's an screenshot of the problem and the css开发者_JAVA百科 code as well.