Installed the UserAgents.7z and had a play.

Try this:

K-Meleon: 74.24 (Windows 7: NT 6.1; Mozilla; Gecko; rv: 24.3)

I found the pattern:

[Browser name]:[Browser version] ([OS name]:[OS version]; [Engine inheritance path]; [Engine name]:[Engine version])

on http://webaim.org/blog/user-agent-string-history/comment-page-4/#comment-88331, and tested it. The only UA analyser to get it is http://www.useragentstring.com/, "User Agent String.Com".

It has not noticeably affected the Sourceforge site, this Forum has always been slow to load on this browser. FWIW, I gave the Forum address to http://www.headerviewer.com/?language=UK, who told me:

HTTP/1.1 403 Bad Behavior
Cache-Control: max-age=172800
Connection: close
Date: Mon, 03 Nov 2014 09:32:27 GMT
Via: 1.1 varnish
Age: 0
Server: Apache/2.2.15 (CentOS)
Vary: Host
Content-Type: text/html
Expires: Wed, 05 Nov 2014 09:32:17 GMT
Client-Date: Mon, 03 Nov 2014 09:32:27 GMT
Client-Peer: 216.34.181.96:80
Client-Response-Num: 1
Set-Cookie: phorum_session_st=deleted; expires=Sun, 03-Nov-2013 09:32:19 GMT; path=/
Set-Cookie: phorum_session_v5=deleted; expires=Sun, 03-Nov-2013 09:32:19 GMT; path=/
Status: 403 Bad Behavior
X-Varnish: 2069203731

Take a dekko at these sites:
https://ellislab.com/forums/viewthread/63850/

https://bugzilla.mozilla.org/show_bug.cgi?id=932498

http://httpcomponents.10934.n7.nabble.com/Getting-status-403-Bad-Behavior-from-a-website-which-loads-fine-in-browser-td14613.html

http://www.mediawiki.org/wiki/Extension:Bad_Behavior

http://bad-behavior.ioerror.us/about/

Gordon.

____________________
Understanding the scope of the problem is the first step on the path to true panic. [Florence Ambrose, "Freefall" 01372 January 22, 2007 http://freefall.purrsia.com/ff1400/fv01372.htm]