These were originally finished in my usual way.
Cellulose sanding sealer, followed by Melamine lacquer, but I have heard of a couple of instances where the same problem has occurred with CA.
I have a wenge pen, which shows the flecking, and I'll post it later.
Mr. Farrer looked at these pens, and has a theory on why this can happen, on certain woods, and I would say he's probably right!
Busy now, but will post later on.