Oh REALLY! That's GREAT.... I didn't realize anyone had figured out a fix, thanks for the info!
I know it was crazy I got it to work. Awesome though. Here's the UESP.
BUGS
XBOX 360, PS3 & PC: Game may not allow you to learn shout at Kilkreath Ruins. Loading a previous save will not fix this; there's the sound of learning a word, and it illuminates yet is never learned. A possible fix for this is to stand next to the wall and while the game is 'attempting' to let you learn the word of power, make the game auto-save (do this by waiting). Immediately after the game saves, quick travel to another location. When you arrive at the other location, re-load the auto-save that was created while next to the wall. A quicker and more reliable solution is to load the save file of another character and then reload the glitched one.
Learning another Word of Power outdoors may complete the bugged Miscellaneous mission to learn the Kilkreath Ruins word, after which you can revisit Kilkreath Ruins to learn "Air". On PS3 this happened by learning "Life" at Northwind Summit; on the other hand, learning the Word at Dead Crone Rock (and several others) did not help at all.
The bug for ps3 also works if you save the game at "create new data" and then load a previous save. (not auto save) And then load the auto save at the shoutwall.