Using cohomological methods we discuss several issues related to chiral
anomalies in noncommutative U(N) YM theories in any even dimension. We show
that for each dimension there is only one solution of the WZ consistency
condition and that there cannot be any reducible anomaly, nor any mixed anomaly
when the gauge group is a product group. We also clarify some puzzling aspects
of the issue of the anomaly when chiral fermions are in the adjoint
representation.Comment: 12 pages, Latex, typos and semantic ambiguities correcte