I've been doing battle with this issue for two days now, and I'm out of hair to pull out.

I followed the tutorials for creating a quest, and while my NPC appears in game, he wouldn't speak. Finally I started another super-simple quest from scratch (with nothing but one line of dialog, and the condition to make sure only my NPC could say it) and the topic appeared in game! (YAY!) but then I went back and JUST recorded a temporary line for it with the CK recording system. I can replay it just fine, and even click the generate lip file, and it seems to work, but going back in game, its back to a mute NPC with no topics.

I've tried recording with a lower quality mic (thinking that my nice stereo mic might be too much for the engine), with no success. I've also messed around with un-checking 'has lip file,' recording again, saving, loading a different sound... nothing.

My roommate in the next room put together a quest, recorded dialog and was just fine.

What...the...hell is going on...?