http://bugs.winehq.org/show_bug.cgi?id=19873
--- Comment #11 from Dmitry Timoshkov dmitry@codeweavers.com 2009-08-29 23:36:55 --- ~/gecko does replace /usr/share/wine/gecko for those who prefer breaking their Wine installation by removing z: mapping. If they know how to remove z: they should know about ~/gecko. Playing games with temp won't help for other things depending on access to root file system like fonts available through font config.
WONTFIX IMHO.