I've had 1.5.8 installed since last night, and I'm sorry to say the song sorting bug has been both fixed and unfixed
Fixed:
When starting a song from an album folder in the "Directory" tab, the playlist is now properly populated in album order, rather than in alpha order (which was the bug introduced in 1.5.2).
Yay! Thanks!
Unfixed:
When starting a song from an album in the "Album" tab, the playlist is properly populated in album order, as before. Fine. But, after powering down, when you power back up, the playlist repopulates in alpha order. Not fine. This means, of course, that if you are listening to an album in this manner, and you need to take a break from listening, your songs will be all out of order when you come back and power back up.
D'oh!
Anyone else getting this same bug?
Edit: Of course, it's pretty easy to re-sort to album order using the menu button on the top right of the playlist screen, but it's still a bug and a minor annoyance.