Just a 'select all' and copy would do, before you hit Post Reply.
If it hangs, do a refresh after a minute or so to see if it takes. If not. exit the browser and try again. Your copy will still be in the clipboard.
I only post on the GalCiv2 site, but it is the same. Buggy and slow. I think they try to do too much with the fancy graphics, instead of simply going with a solid (and perhaps plain) website.
I am less impressed with glitz, than I am with functionality.