http://bugs.winehq.org/show_bug.cgi?id=26854
--- Comment #6 from Austin English austinenglish@gmail.com 2011-04-20 16:57:12 CDT --- For me with git, I don't get a 404, but instead the site silently rejects my password and sends me back to the login page.
If I do the same with Firefox4 under wine, when my password is rejected, I get a small embedded popup saying my password is invalid and to try again.
So, there is a bug (that popup is missing), but I'm not sure it's worth the trouble to debug, given the geographical/other restrictions.