http://bugs.winehq.org/show_bug.cgi?id=29524
--- Comment #3 from wum46 wu.m@arcor.de 2012-01-03 08:58:50 CST --- The same happens also when I call Firefox under Wine from the command line, without giving a file to view - that is how I created the attachment I just posted.
Since there is a workaround (namely forbidding Firefox to do automatic upgrades), the importance may possibly be reduced.