There’s a couple of bugs that deal with icons being inappropriately scaled. Not only does scaling a 48x48px icon down to 16x16 almost never work, but even scaling a 24x24px icon down to 23x23px ends up in a blurry mess.
It’s great to have a caring hacker around. I’d like to appeal to all other GNOME developers to follow the same algorithm. The pixel-precise desktop icon nirvana is on the horizon.