I've tried various attempts to set-up shortcuts on the numeric keypad with the Settings Manager, under Keyboard / Shortcuts, with both NumLock on and off as well as Ctrl as a modifier. Pressing the keys nearly always results in the default action being sent to the active window rather than being overridden. The same bindings *do* work under Window Manager / Keyboard, but those actions are fixed 'window shortcuts' that don't provide the required functionality.
There seems to be a similar issue with one or two other keys - the Keyboard Preferences / Shortcuts editor allows you to define against keys but doesn't trigger the event when those same keys are pressed, e.g. the left 'Windows' key on a modern keyboard shows as 'Super+Super_L' but both it and the right 'Windows' key are ineffective.
This bug has also been reported on Ubuntu Launchpad as: https://bugs.launchpad.net/bugs/630722 From the launchpad report: Version of xfce4: 4.6.1.3 I use Xubuntu 10.04.1. Keyboard shortcuts including number keys in number pads do not work. You can use non-number keys in number pads such as "*"(MULTIPLY) and "+"(ADD), but number keys ("0", "1", ...) won't work. Reproduction Procedure: 1. Activate "xfce4-settings-manager". 2. Click on "Keyboard", select "Application Shortcuts" tab. 3. Add a shortcut. Command : zenity --info Shortcut: KP_Divide (Type "/" in your number pad) 4. Hitting "/" key in the number pad shows a dialog box. 5. Then, add another shortcut. Command : zenity --info Shortcut: KP_6 (Type "6" in your number pad with NumLock on) 6. This time, hitting "6" key does not show any dialog box. I tried <Control>KP_6, <Alt>KP_6 and <Super>KP_6 too, but none of them worked. I tried some other number keys in the number pad, but the result was the same.
This bug still exists in 4.8.1 on Arch Linux and is really annoying.
Created attachment 4626 Patch for xfce-shortcuts-grabber.c Fix for Numeric-KeyPad keyboard shortcuts
Fixed. I installed a fresh current xubuntu 12.04.1 and verified that the failure persists as reported in Comment 2. Then I built and installed libxfce4kbd with the above patch (Comment 4) and verified that the Comment-2 procedure yielded the desired results, namely, hitting KeyPad 6 results as expected in executing the shortcut command correctly. I noted that Fedora 17 xfce did not have the problem, so I compared its libxfce4ui source with xubuntu 12.04.1's. Only the single source file was different, and so thanks go out to whoever made that fix in Fecdora-17-xfce. Thanks to killermoehre@freenode:#xfce who suggested to me (richtroye) that this bug be worked on!
Still happens on Xubuntu 12.10, which has Xfce 4.10 KP_0 through KP_9 do not work. KP_Divide, KP_Add, KP_Subtract, and KP_Multiply however do work.
Fixed in git master of libxfce4ui with commit 6633a2deed6ab60fbb02c157a8c9499c1824fb4e.
*** Bug 9923 has been marked as a duplicate of this bug. ***