Tone changed after gluing fingerboard down

[vibrolucky]

So around Thanksgiving, I finished my first really nice build. Basically an OM-28 style hybrid (body thickness 3/4" thicker than Martin OM).

Pleased with the tone and was making some final tweaks on the setup, its a bolt on neck so I decided to go ahead and glue the fingerboard extension to the top after it was setup properly. Too my suprise, I noticed a remarkable change in tone, sustain and volume (for the worse). It was measurable not just to my ear, but others who played this guitar before and after. Put some fresh strings on just to take that out of the equation.

Fortunately we used hide glue, and used it sparingly so removal should be fairly painless. Anyone ever experienced this phenomenon?