It could be a simple case of a loose clip behind the passenger side A-pillar trim? It's really hard for me to say. Some TSXs had a creaky windshield in the '04 model year many-many different solutions were found to be needed, including reinstallation of the windshield.

I would suggest you simply find a new dealer, since I assume your are under warranty they should fix this not you. It may be normal, but IMO unacceptable.

We had a creak in our TSX, it was the plastic trim on the rear of the rear view mirror, I simply adjusted the trim where it met the headliner, no more noise.