Hi BIB,
If  this is the R21 model with the digital display:-
press both the POWER FREEZE & POWER COOL buttons at the same time for about twenty seconds, the unit will beep and reset.
You will have to do this everytime the unit is disconnected from the power.
this took me 3 weeks to find this shortcut with no help from Samsung
                
 sm
                
 December 2009