Brad,
I had the same problem after the update to the site. In my case I found that, while in the REPLY mode, if I clicked on the last ICON on the right just above this typing box named Toggle View (when holding the cursor over the ICON) it will resize the response box to normal size and the word wrap work again. At first I had to click it each time I responded to a thread but then it "stuck" and now all is working normally.