[imp] IMP HordePopup PDF attachment Firefox Window "about:blank" on some profiles

[Samuel Wolf]

Hi,

I have some Firefox profiles which show a blank (popup)window  
(about:blank) and then open Evince as expected if i click direct an  
the attachment name.

First guess was a error in the Firefox profile, but a complete new  
show the same issue.
On the other side i have a Firefox profile which show short the blank  
window, close it and open Evince.

Any idea whats wrong with my Firefox profile?

Samuel