This is thread may need to get moved. I'm not quite sure if it is in the right place.
I am on a Nokia Lumina 920 right now and am experiencing a bug when attempting to write the body of a thread, the body of a comment, a quick reply, or a pm. Rep comments and titles do not have this problem.
Basically when I click to type in the body my keyboard pops up and immediately drops back down. If you are really fast you can type 1 letter. I have found that if you manage to hit paste in this small window of time the keyboard locks open.
I will also note that I tried this on my coworkers Nokia 920 and had the same issue leading me to believe that the problem is not local to my phone but probably an issue with all windows phones. Any trouble shooting would be appreciated and I will try anything if you need more tests.