How strange! It must be said that MultiAVCHD's interface is quite dense and often unintuitive, so it's quite possible that an option hasn't been properly enabled/disabled on one of the authoring screens. Can you re-check your project for 'compatibility features' (probably around the menu area)?

It's unlikely that you will be able to convert the existing disc to a compliant structure and still retain the menus. ClownBD is an astonishingly good tool that can take almost anything (including HD-DVDs) and turn them into compliant BDs, but the result is movie-only.

Just to answer another question, I couldn't recall if I'd tested Halloween yet so I had a look in my Panasonic standalone. It loads and plays smoothly, no issues. Navigation is a little slow (chapter searching and scanning) but I've often found that to be an issue with x264 encodes - it's certainly not particular to your projects.