It took me ages to find this, and now I am happy.....
DEPENDANT OF EU/SPANISH NATIONAL
IMPORTANT NOTICE: Under Directive 2004/38/EC and according to Real Decreto 240/2007, 16 February, Family members of an EU/EEA National in possession of a valid UK Residence Card are not requiered of a visa to enter Spain. Please note that the UK Residence Permit must state literally that the holder is a family member of an EU/EEA National,
http://www.maec.es/subwebs/Consulado..._services.aspx