Hi Luca, 

Maybe it is a right time to update your actuator plugin. There are some changes in vdr-1.7.23,  it is enough to change SystemValues to SystemValuesSat to compile vdr-actuator against the last vdr-1.7.23, or simply:  
sed -i -e "s/SystemValues/SystemValuesSat/" actuator.c


Regards,

Yarema