I haven't had access to a PC or Mac for a while, so I've been learning skills via my iPad. (Who's addicted?) There is a bug on (at least) the iPad 2 with iOS 4.3.3.
Go to the Glitch skills web page. Click on a skill icon. A yellowish popup appears that tells you about the skill but doesn't give you a button to learn the skill. Persistent tapping on the skill icon will also bring up another popup, this one larger and white, with a bluish central stripe. It also tells you about the skill, but this one has a button that says (something like) "Learn this skill now."
I wonder if one of these is left over from a previous code base and shouldn't be invoked now? In any case, the one with the button often appears *under* the yellowish one, with the button barely visible. So that's, you know, not ideal.