'Save As' does not work

Hello. My 3.0.6 Firefox portable has a problem with saving files.

When I click on a link to save any file the 'save as' box apears but the 'save button' does nothing, ie, the file won't be save. Now I oberved that the 'save as' in 'menu file' does not work too. I can not save the pages also.

Any idea?
Regards.