I had this issue since launch. I used the "Walsh-method" of putting NoDo on my phone and haven't noticed it since.. here's to hoping it's gone for good. Turning key-click off was not an option because not hearing the clicks was the only way I noticed that they keyboard had stopped responding.
For me, it happened with no memory card, an 8GB Class 2 and a 16GB Class 4, so it has nothing to do with the memory card. I also tried turning off feature where I could "teach" the keyboard new words, and that also didn't help. Turning WiFi off wouldn't effect it because I don't use WiFi to squeeze extra battery life out of it. I'm not sure what's causing it, but from what I could tell, nothing that I changed on the phone would effect it in any way. It would happen to me a few times a day, both in portrait or landscape. Hopefully, you'll only have to deal with it a few more days
@duvi it only seemed to happen (to me anyway) in the SMS app.. at least I never noticed it happening anywhere else. Maybe in Hotmail a few times? Primarily SMS, but that's primarily where I use the keyboard.