Is anyone else getting frustrated by this? I start replying to a post, scroll up to copy some code from the original post (like the code I'm fixing), and then find that I can't click in the reply box. I can tab into it, but it doesn't respond to the mouse.
On closer inspection, it seems that the ads are sometimes failing to load, and when they do the iframe that should have contained an ad is positioned in front of the reply box. You don't see anything, because it's invisible, but it catches all the mouse clicks.
If you're having this problem (in Chrome anyway), right click on the reply box and select "Inspect". You'll see the page's HTML source with an
<iframe … block highlighted. Right click on
<iframe and choose "Delete element". Then you can continue with your reply.
I hope that this is a temporary bug and will be fixed soon :S