No, no bookmark file created in the directory.
I tried bookmarking in another playlist - worked fine, both the auto-bookmark when pressing stop and the manual bookmark.
Nothing wrong with the settings then. Must be the playlist.
What differs between the playlists is:
1. The non-working is LARGE - +5,000 entries
2. The non-working has been altered since creation.
Saw somewhere that when you alter a playlist it must be re-saved. But it's impossible to re-save the current playlist - "File not accessible".
FYI: My large non-working playlist is a scramble of ALL my music. I want to go through it all and make purposeful smaller playlists for different "moods" (jogging, relaxing, dancing, romancing etc.) Would be nice to be able to side-step this long process occasionally to listen to a specific track, without loosing track.