For all of the bullcrap hoops you have to jump through to style this element, it's so much simpler to just use a short div instead. It's far more flexible, it's block-level so you can do more positioning business if that inflates your date. Not to mention you don't have to do a bunch of browser-specific nonsense to control things like color (IE thinks the color of an hr is a foreground color, Firefox and Opera a background color - no clue where Webkit stands on this).

So, the next time you want to use an hr, try something like this instead:

And then margin the hell out of it to move it around. Done and freaking done, browser crap evaded.