I have arrived at the castle gate after going through the hedge maze in Raquia. The gate is closed and the voice tells me (to paraphrase) that the gate is closed to me and to go back into the maze. I have the earplugs, pan flute, jewelled turkey leg, and ring in my inventory. These are the only things I've picked up in Raquia. I have spoken with Rebecca about everything. According to the two or three walkthroughs I have consulted, the gate should be open as far as I can tell.
Joy, joy! I finally made it. I found another walkthrough that said to put the turkey leg in your gun hand and walk straight to the gate. I took special care to walk very straight while weilding my turkey leg with the ring on my right hand and that seemed to work. It's past my bedtime so maybe I just missed something simple.