Fixed a little issue just now that caused the sigs to be broken on some loads.
The problem is that twitter's CDN sometimes drops the ball a bit and can't serve up your twitter avatar. When that happened, it just failed with a "something's gone wrong" message, which isn't an image, so you ended up with gooseberry fool like this:
Now, if it can't find your avatar, it fails more gracefully to the default twitter avatar. That's just a quick and dirty fix, though. I'll have it cache your actual avatar next time I do an update, and only try to pull it from twitter if it's changed.