Thank you! Someone else pointed out that Dictionary doesn't accept an offsets buffer, therefore it should have been:
column_vectors.push(Vector.new(Data.Dictionary(new Dictionary(new
Utf8(), new Int32()), 0, element_count, null_count, nullmap_buffer,
interned_buffer, dictionary)));
-- i.e. without the zero after nullmap_buffer. This solved the problem.
Yakov Galka
http://stannum.io/
