Above is a container with a blue border and tan background. The lower part of the container is unstable. Move another window over the lower part of the container and the border, background colour and content will disappear. Below is the CSS needed for the bug.
#leftColumn {
padding-bottom: 381px;
}
#mainContent {
background-color: #EFECC9;
}
.clearit {
height: 0;
}
A similar peekaboo bug IE/Win: peek-a-boo like problems by Bruno Fassino is also caused by the clearing div having height:0. A normal comment must appear inside the closing tag of the container div or between the container and the clear div (red border) in the source code.
<!-- normal comment -->
The problem can be fix by giving the container hasLayout.
Depending on you connection speed, as you enter the page or referesh the page, the container and the text within maybe not be rendered. Resize the window, scroll the window, move another window over this window or switch windows and return to this window and the container and text appears, but the bottom part is missing. If you resize the height of the window to be shorter until the bottom edge of the viewpoint touches the green float, the whole container is rendered and if you resize the height of the window to be longer, the bottom of the container is missing again. If the window is not high enought for the whole float to be seen, then the bug is not seen.