This definitely looks like a screen resolution issue, and not so much a bug. I tried adjusting my browser window so that it was small enough to cut off the badge window, and I saw the same effect as you; once you have the badge list open, you cannot scroll the main page.
Two solutions that worked for me:
- Close the badge window, scroll the main page down just a bit, and then re-open the badges. The badge window should have moved slightly with the rest of the background.
- Zoom out on your browser (
scroll) until the whole badge window is visible. This also makes all of the text smaller, so it may not be the most desirable solution.