Acrobat Reader opens when not asked
 

Hi !

I'm at my university's computer district (this means I can't be root), and I experience the following problem :

Acrobat reader starts in replacement of other pdf viewers.
- When I'm using nautilus, and I double-click on a PDF, it is opened by acrobat reader, not by evince as specified in the configuration (I double-checked, put evince as default, but nothing will do).
- When I'm using firefox (2.0.0.1 or 3.x), if I click on a PDF link, it will open in acrobat even if evince is set as default, but if I close acrobat and open the Downloads window (ctrl+Y) and then click on open, it opens with the right program
- I have no mention of "pdf", "acrobat" or "reader" neither in about:config, nor in about: plugins.
- If I open a terminal and enter evince <filename>, then it works.
- Same behavior for kpdf.

I don't want to use acrobat because 1) it's not free/libre, 2) it's junk, other programs are far better.

Does anyone have an idea about *where* acrobat could do it's mischeif ?

Would be useful to know what distribution you're using!