I have this strange problem on my laptop.
If in the Display manage settings I set the Auto Login checkbox the Ctrl-\ keys combination doesn’t work in the Italian keyboard.
Running xev, when I press Ctrl-\ I have:
KeyPress event, serial 48, synthetic NO, window 0x2e00001,
root 0x155, subw 0x0, time 63651, (116,6), root:(207,261),
state 0x0, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False
FocusOut event, serial 48, synthetic NO, window 0x2e00001,
mode NotifyGrab, detail NotifyAncestor
FocusOut event, serial 48, synthetic NO, window 0x2e00001,
mode NotifyUngrab, detail NotifyPointer
FocusIn event, serial 48, synthetic NO, window 0x2e00001,
mode NotifyUngrab, detail NotifyAncestor
KeymapNotify event, serial 48, synthetic NO, window 0x0,
keys: 85 0 0 0 32 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
KeyRelease event, serial 48, synthetic NO, window 0x2e00001,
root 0x155, subw 0x0, time 64704, (116,6), root:(207,261),
state 0x4, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False
where the backslash key in not recognized.
If I do not enable the Auto Login feature the Ctrl-\ key combination works as expected and the backslash key is recognized; running xev:
KeyPress event, serial 48, synthetic NO, window 0x3c00001,
root 0x155, subw 0x0, time 2428896, (1198,72), root:(1199,122),
state 0x0, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
XLookupString gives 0 bytes:
XmbLookupString gives 0 bytes:
XFilterEvent returns: False
KeyPress event, serial 48, synthetic NO, window 0x3c00001,
root 0x155, subw 0x0, time 2429248, (1198,72), root:(1199,122),
state 0x4, keycode 49 (keysym 0x5c, backslash), same_screen YES,
XLookupString gives 1 bytes: (1c) ""
XmbLookupString gives 1 bytes: (1c) ""
XFilterEvent returns: False
KeyRelease event, serial 48, synthetic NO, window 0x3c00001,
root 0x155, subw 0x0, time 2429391, (1198,72), root:(1199,122),
state 0x4, keycode 49 (keysym 0x5c, backslash), same_screen YES,
XLookupString gives 1 bytes: (1c) ""
XFilterEvent returns: False
KeyRelease event, serial 48, synthetic NO, window 0x3c00001,
root 0x155, subw 0x0, time 2429453, (1198,72), root:(1199,122),
state 0x4, keycode 37 (keysym 0xffe3, Control_L), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False
Regards
Maurizio