Re: Question about Thunderbird version in User-Agent header line

> For examples, look at this newsgroup thread in Google
    
http://groups.google.com/group/mozilla.sup****t.thunderbird/browse_frm/thread/daf11b46384f70a4

I notice that the first two posts in that thread have this as the user
agent:

   Thunderbird 2.0.0.9 (Windows/20071031)

While the third post has this:

   Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.9) 
   Gecko/20071031 Thunderbird/2.0.0.9 Mnenhy/0.7.5.0

What determines (or why is there) such a difference in the string that
is created for the User-Agent?  Especially since they seem to be the
same version of Thunderbird (2.0.0.9) ?