Different CSS border priorities

I’ve found an annoying difference between IE/Win and just about any other browser on Mac and PC when specifying different colored CSS borders to each side of an object. For instance, I have a navigation item where I’m specifying a 2px left border, and a 1px bottom and right border to create a 3D effect. This works fine on IE Mac, Chimera, Netscape Mac and PC. Example is shown below:

css on IE Mac

On IE/Win, the browser, very annoyingly, prioritizes the order of the borders by making the bottom border span across the entire width of the item, rather than making the left border the priority and having it span the entire length of the left side of the item. Example of IE/Win below:

css on IE Win

I haven’t been able to find a workaround for this so if you happen to know any tricks, let me know.