This turned out to be a Firefox issue. Solution is here: http://support.mozilla.com/en-US/kb/Mouse%20buttons%20do%20not%20work%20as%20Back%20and%20Forward
Thanks for your help, Panayiotis -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4d823c3d.8040...@gmail.com