What I want to achieve is have some kind of news- / menu- box with dynamic size. But since the box border (left and right) is kind of random (Picture: http://imageshack.us/photo/my-images/193/menusjo.jpg/), I need to make sure that the the left and right border (table background images) have (dependent on the current box-size) the correct size.
Since the box-size its self is fixed by its content, I achieve this by changing background-size of both left and right table cells (eg. I make sure, that background-size is set to the best integer multiple of the actual image, this might scale the image a bit [not much], but makes sure, that left and right border fits to the box footer).
This works really well in Firefox, but when I use IE9, the background-size does not take effect (the background images aren't scaled at all).
I tested a few other background-size examples and it looks like IE9 does not support background-size when background-repeat is enabled (repeat), for no-repeat it works.