client/MouseDown() and atom/MouseDown() fail to trigger every time the mouse is pressed. They only seems to trigger every other click, possibly due to some sort of internal double click interference? Using Click() will trigger every time (even during a DblClick). This MouseDown issue seems to extend to DS in general, and will not trigger if you spam click a verb in a stat panel. However, if you set an interface macro for that verb, the key will properly trigger it every time.
Demo: http://www.angelfire.com/hero/straygames/ByondBugs/ MouseFails_src.zip