I'm using WebKit-SVN-r30574 with Safari Version 3.0.4 (5523.15) on 10.5.2. Clicking on that link downloads a corrupted file, senuti_0.50.2b3.dmg.bz2, that won't expand properly. The same link clicked on in Firefox downloads and can be properly expanded into a good dmg.
mrowe@daisy:~$ curl -s -i http://senuti.googlecode.com/files/senuti_0.50.2b3.dmg | head HTTP/1.1 200 OK Content-Length: 4825300 Content-Type: application/x-bzip2 Content-Disposition: attachment; filename="senuti_0.50.2b3.dmg" Accept-Ranges: bytes Expires: Thu, 06 Mar 2008 00:00:00 GMT Cache-Control: public Server: DFE/largefile Date: Thu, 28 Feb 2008 08:41:47 GMT The server is claiming the MIME type is application/x-bzip2, which results in a .bz2 being appended to the filename. This behaviour is almost certainly outside of WebKit, either in the CFNetwork HTTP stack or in the Safari application itself.
<rdar://problem/5770501>
Closing as INVALID per our policy for handling bugs that are in components of Mac OS X outside of WebKit. The bug report will be tracked inside Apple via the Radar mentioned above.