>I know a lot of Europeans who grew 
up watching this version of Heidi on TV -- I 
think in Spain>

Actually,this was a cult series in Austria, 
Switzerland and Germany, actually it reruns since 
ca.1979 and ask a German of any age and 90% will 
say, they know the show!(at least, for the silly 
opening song^_^)
I heard also, this show is very popular,among  
many Japanese, because of the "fairytale" 
backdrop. (Switzerland being one of the favourite 
countries, for Japanese) ^_^