For me all the messages show fine, all testing done in advanced client w/ ff 2.0.0.11, tried all reply/forward options, logged off each time, in both html & text, new window or same window, clearing browser cache occasionally etc, etc.
I've had no blank bodies, their all included when asked ("don't include" and "include as attachment" settings work as expected) minus the 'include just last' which includes all.
However prefixes don't appear, just like this person had on RC2
Using ">" or "|" for original message when replying
Though I have not been able to reproduce this on any personal box or client boxes.
Dan just took a look and concurs that: "Body appears but the prefix character is not happening - I tried a couple times, including logging off & back on, same response every time. I dunno about not getting the message at all; it works for me"