Sorry guys but I just returned from Christmas party
--edit
The fact that you could not use /tmp as mountpoint is strange, /tmp is a symlink to /rw_fs/tmp and that directoy is world r/w should you should be able to create a folder there to be used as mountpoint :scratch.
Using the command reboot is not enough. A bit must be set in an eeprom to set proper shutdown/reboot method.
Use the the restart or shutdown buttons in the web interface of fvdw-sl firmware that should solve this problem as they set the eeprom correctly.
To reset it pull the power plug and press power button several times to drain all power. Wait a few minutes and then put power plug in and press the power button if it doesn't boot by itself. When you have once shut it down with fvdw-sl webinterface buttons then it should boot automatically when restoring power.