Tried again to post a reply to a clutch-fan thread and it worked this time. Typing this is working too. When it quirks, it acts like perhaps popups keep taking focus away so the cursor is no longer on the text. You must click again to reset the cursor and continues happening. When you hit return, the line above moves down. Can't paste text. Finally, when you click "Post Reply", it fails to post. Has happened many times over the last 6 months.
