I understand what you are saying, but still think it's very strange.
I have another entity that has a field declared as a map and the entity inside the map has Strings fields.
I search and sort those String fields while restricting by id, just like the example above, and that also works.
It really looks like the problem is specific with long fields. I tried to debug the Lucene classes and I saw that the long field is mapped in a place that the double field isn't, and that's what's causing the problem, it wouldn't throw exception otherwise...