I would suspect a power booster in the Antena that was suggested before.

Wait - reality check. Do you mean get a stronger antenna (like the S2000) or you suspect the Honda antenna DOES require a connection from the "Power Antenna" lead (to who knows where).

Perhaps there's something in the stock tuner that takes care of it.

(Sorry if I'm sounding dense again - doesn't this remind you of the whole crossover discussion again?)