I've had this trouble the last couple of days. Using the Quick Reply feature, I've been getting "stuck" without the reply going through. I thought it might be me Internet connection, but everything else seemed fine.
I've been doing what was just mentioned above, copying the text I'd just written in the reply, and reloading the Forum. I've found that the Quick Reply doesn't seem to go anywhere, but the "Reply" button, which also gets you stuck, DOES send your post through, even though it just sits there.
I've called the Forum up in another IE brwoser window and could see that just using "Relpy", my post actually went through, though the original screen never finished its posting.
My guess is that people are hitting the "Submit" button in frustration, causing double posts.
Harry