FILTER EQ returns no results sometimes

[dewtoujii]

The following query works as expected and returns two cities named "Berlin":

PREFIX fb: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?cityname ?countryname WHERE {
?city fb:type.object.type fb:location.citytown .
?city fb:type.object.name ?cityname .
?country fb:type.object.type fb:location.country .
?country fb:type.object.name ?countryname .
?city fb:location.location.containedby ?country .
FILTER(?cityname == "Berlin"@en) .
}

But filtering by country "Germany" does not work and return 0 results:

PREFIX fb: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?cityname ?countryname WHERE {
?city fb:type.object.type fb:location.citytown .
?city fb:type.object.name ?cityname .
?country fb:type.object.type fb:location.country .
?country fb:type.object.name ?countryname .
?city fb:location.location.containedby ?country .
FILTER(?countryname == "Germany"@en) .
}

Changing the filter to NEQ (!=) seems to work because the result size reduces from 180549 (without any filter) to 174112:

PREFIX fb: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?cityname ?countryname WHERE {
?city fb:type.object.type fb:location.citytown .
?city fb:type.object.name ?cityname .
?country fb:type.object.type fb:location.country .
?country fb:type.object.name ?countryname .
?city fb:location.location.containedby ?country .
FILTER(?countryname != "Germany"@en) .
}

Also the result sizes of the filters (<=) and (>=) add up to 180549