Regarding my problem with the DX100 playing albums in the wrong order, the following fixed it:
(1) First, verify all your tags are correct and sane (mine were).
(2) Completely delete the music in question from your DX100.
(3) Unmount, disconnect USB, wait for the DX100 to re-index your catalog. This is the most important step: letting it re-index and noticing the music is gone.
(4) Re-connect USB, mount, copy the music back over.
(5) Unmount, disconnect USB, wait for the DX100 to re-index your catalog again.
Further note for you Unix types out there: don't use rsync for copying music to the DX100, as the way rsync uses temporary file names during transfer and then renaming them when complete, I think, is the reason the DX100 was ordering these songs incorrectly. It seems to care more about the order files were written to the media than the actual tagged track number, which is completely ******* braindead, but then again, this is the DX100 we're talking about here. Wouldn't want to blow anyone's mind with sane media handling!