In terms of the "form no longer value" issue, I have found this to happen when using quick reply, but not when using reply or quote. In other words, those seem to work fine.
When it has happened, I was always able to use "back" in my browser and there is my text, which I then copy and paste into a reply.
It does not work when cookies are off.
My browser is Safari and I use a Mac, so on a PC YMMV.
But there does seem to be a slight bug in the "quick reply" function.
Now back to our previously scheduled topic, which is already in progress...