I had the first two words of the Ice Form shout, but hadn't activated it. Then, when out adventuring, I stumbled across a wall in a dungeon that had the third word, when I went up the wall I was shown that I had all three words. Thinking this was neat, I immediately tried to activate the shout but was shown only the first two words. I went straight back to the wall but it was now silent. I activated the shout anyway, thinking that perhaps I might be allowed to fire up the third word later, but several game days have now passed and nothing has changed. I have plenty of Dragon souls "in stock". Regrettably I have no save game from before I went to the wall, well I do have a couple but they are very old, and I don't feel like playing through again.

Has anyone any idea why this has happened? Does anyone know of a way round it (I ma on a PC and have no objection to using the console commands to fix glitches)?

Edit: Stand down re the last bit I have found the console command via Google. I'd still be interested if anyone else has had this problem and what could have caused it, though.

Sometimes the game doesn't reset everything to the original state when you reload without exiting to the main menu first, so maybe that was the issue here.

So you could try to reload the game before you got to that wall, or use "teachword 00070980" in the console.