The title says it all. It has ceased to work. Before I used my middle mouse button to issue a command-click and it would open a new tab - now nothing.
Prefs are set right, USB overdrive is set right (for my Logitech to use middle button). Holding down command and giving a single click does nothing, double clicking opens the tab.
It works with my mouse in Camino still, and Firefox, and used to work in Safari; but no more.
Help much appreciated.