http://bugs.winehq.org/show_bug.cgi?id=16310
--- Comment #5 from Reece Dunn msclrhd@gmail.com 2008-12-03 02:45:54 --- I also had a look at that specific patch and couldn't see anything wrong with it.
Maybe, as you said, the issue is transitory and/or environmental. I only ran the downloader once in each bisect, so if it is an intermittent failure then the bisect results would be unreliable - hence it picking up a good patch.