navigation shotcuts

[OrB]

in main i want to request the support of the mouse-buttons 4 and 5 of a 'normal' 5-button mouse
which are used to navigate in a browser backward and forward

i think therefore are needed the shotcuts for the MB 'Browse Back' and 'Browse Forward' buttons
in Firefox the keys are :
Browse Back    Alt + (Arrow left) or Backspace
Browse Forward    Alt + (Arrow right) or Shift + Backspace

if i delete the multimedia-shortcuts (test) and use the mouse-buttons 4/5
a error occurs - posted to bugreports as: navigation shotcuts (bug)