Insteon PLU & Keyspan USB/Serial

I have a #2413S PLM connected to my Vera Plus (version 1.7.3532) via a Keyspan USA-19. Vera seems to add the PLM okay far as I can tell.

I cannot get Vera to control X-10 devices. Clicking the on icon results i a twirly thing for a few seconds, then the highlight moves back to the OFF icon.

I tried removing the PLM and re-adding it, same behavior.

I had thought this configuration should work. Am I wrong?