I'm not having any problems either. Try accessing the site with a different browser and see if you still can't see what's typed in the threads. Should you still have the same issue then maybe it could be a "specific browser" [or is it browser specific?] problem.
The only strange thing I normally see is: I start typing text. I switch to italicized text. I switch back to regular. If I hit backspace at any point from there, the cursor jumps to the first not italicized word and deletes that character. No biggie, but certainly weird.
