It does seem to be a particular problem in certain Eastern European countries.
Almost backed up by this list off of BBC
Uefa's sanctions against clubs for racist behaviour this season
Full stadium closures: Dinamo Zagreb of Croatia, Legia Warsaw of Poland and Honved of Hungary
Partial stadium closures: Lazio (originally handed a full stadium closure that was reduced on appeal), Polish clubs Lech Poznan and Piast Gliwice, APOEL Nicosia of Cyprus and Croatian outfit HNK Rijeka