OS X 10.8 can't open AVCHD files on NAS

franklahm wrote:
I'll look into this.

It's a case sensitivity issue. As you may know OS X filesystem is case insensitive, ie you can't have two file "test" and "TEST" in the same directory and the OS X API will return the entry for "test" when asked for "TEST". By contrast, the NAS uses a case sensitive filesystem and Netatalk (the opensource AFP fileserver running on the NAS) runs on top of that.

Unfortunately, the Finder mechanism for detecting whether a simple folder containing AVHCD media shall be presented to the user like a file is based on the Finder inspecting the folders contents behind the scene, looking for a file INDEX.BDM nested somewhat in the folder hierarchy:

FOLDER/PRIVATE/AVCHD/BDMV/INDEX.BDM

Now, as long as the folder is stored on a Mac (HFS+ filesystem, case insensitive) it doesn't matter if the Finder looks for the file by the name "index.bdm" or "Index.bdm" or "INDEX.BDM", all names will match the filename. But when you copy the folder to the NAS unit case matters.
Unfortunately the Finder looks for the file twice (verified with a network traffic analysis): once with the exact name "index.bdm" and then later with "INDEX.BDM". So no matter which case the filename has, both searches can't equally match on a case sensitive filesytem.
I recommend filing a bugreport with Apple, they're really the only one who could fix this.