Special keys (dim display, lock screen) don't work anymore on intrepid wiht my X61s

I have a Thinkpad X61s and the special keys, like Fn+F2 for locking the screen or Fn+End for decreasing the brightness of the screen, used to work until I upgraded to intrepid (by accident).

Actually nothing visible happens, but It seems to recognize the keys correctly as xev shows:

KeyPress event, serial 117, synthetic NO, window 0x3600001,
    root 0x6d, subw 0x0, time 895905, (149,265), root:(159,330),
    state 0x0, keycode 160 (keysym 0x1008ff2d, XF86ScreenSaver), same_screen YES,
    XLookupString gives 0 bytes:
    XmbLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyRelease event, serial 119, synthetic NO, window 0x3600001,
    root 0x6d, subw 0x0, time 895909, (149,265), root:(159,330),
    state 0x0, keycode 160 (keysym 0x1008ff2d, XF86ScreenSaver), same_screen YES,
    XLookupString gives 0 bytes:
    XFilterEvent returns: False

KeyPress event, serial 119, synthetic NO, window 0x3600001,
    root 0x6d, subw 0x0, time 897143, (119,190), root:(129,255),
    state 0x0, keycode 9 (keysym 0xff1b, Escape), same_screen YES,
    XLookupString gives 1 bytes: (1b) ""
    XmbLookupString gives 1 bytes: (1b) ""
    XFilterEvent returns: False

Fair enough: Increasing brightness with Fn+Home works. Also I hit this "Up-Key opens gnome-screenshot" issue every now and then, e.g. not every time I boot up, just 50% of the time.