I have the same problem too, but in my case it seems that firefox doesn't close properly if (but not only if) during my last browsing I have visited the page: http://www3.uninsubria.it/uninsubria/facolta/scico.html
Maybe it has something to do with the embedded java frame.
I have the same problem too, but in my case it seems that firefox doesn't close properly if (but not only if) during my last browsing I have visited the page: www3.uninsubria .it/uninsubria/ facolta/ scico.html
http://
Maybe it has something to do with the embedded java frame.