Corner Rounding on Android 2.2

Corner Rounding on Android 2.2

Here's a deployment that's using the latest release from github:  www.cyclistthegreat.com

If you look at this on Android, you'll notice that the gear icon, the home icon and even the back up have noticeably jagged edges and are essentially unusable in this state. It renders fine on desktop browsers and iPhone.

I've checked the live demo site and see the same issues there, though they're not as noticeable if it blends in with the background color. Can this be fixed or should I revert to square borders?