Different browsers uses different font sizes. That was the reason for the content of setup pages is displayed to the right of the right edge of its tabs with some browsers. Even with the same browser if you change the font size you could see the bug coming. 

For taking the vertical position of the "contents" the code used "em" in css which depends on the font size. So I changed the "em" to "px" in some places to get rid of that dependency. Now the contents are not moving to the right edge even the font size is changed.