iceweasel 3.5.6: does not recognize file extension (pdf, zip)

[Mathieu Malaterre <mathieu.malaterre@gmail.com>]

Hi there,

  I update my iceweasel package to 3.5.6 and now I cannot double-click
on downloaded zip file or pdf file. Everytime it asked 'Launch
Application' where I need to manually 'Choose an Application'. Does
anyone knows what could have happened ? What should I do to get back
the original behavior (as in the older iceweasel release).

Thanks
-- 
Mathieu