shanti: I just checked, you are right, somehow that configuration got lost in the latest version! See, this is what beta-testing is all about. Next version will have this again.

For now, here's how to get it working again.

Edit this file: /home/user/.config/openbox/lxde-rc.xml

Find the section:

<!-- Keybindings for windows -->

Add the lines:

<keybind key="F4">
<action name="Move"/>
</keybind>