IE9 is apparently able to handle rounded corners by using the CSS3 standard definition of border-radius.
What about support for border radius and background gradient? Yes IE9 is to support them both separately, but if you mix the two the gradient bleeds out of the rounded corner.
I am also seeing strangeness with shadows showing as a solid black line under a box with rounded corners.
Here are the images shown in IE9:
How can I work around this problem?