After upgrading to Linux Mint 16 that comes with xfce4-session 4.10.1-1ubuntu1 and xfce4-xkb-plugin 1:0.5.6-1 the issue doesn't occur anymore. Just the Num Lock LED still gets inverted, but that's a different story related to the evdev driver. I reported that in the Red Hat Bugzilla and trying to resolve the issue with Peter Hutterer. Thank you.
After upgrading to Linux Mint 16 that comes with xfce4-session 4.10.1-1ubuntu1 and xfce4-xkb-plugin 1:0.5.6-1 the issue doesn't occur anymore. Just the Num Lock LED still gets inverted, but that's a different story related to the evdev driver. I reported that in the Red Hat Bugzilla and trying to resolve the issue with Peter Hutterer. Thank you.