XFCE4 Ubunbu not recognize tab key via VNC

Easy fix via http://ubuntuforums.org/archive/index.php/t-1771058.html

Open file

~/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-keyboard-shortcuts.xml

find the line

<property name="&lt;Super&gt;Tab" type="string" value="switch_window_key"/>

and change it to

<property name="&lt;Super&gt;Tab" type="empty"/>

Or in terminal (via http://blog.zerosum42.com/2011/10/tech-fixing-tab-key-in-vnc.html):

xfconf-query -c xfce4-keyboard-shortcuts -p /xfwm4/custom/''Tab -r