The uncritical, pro-manufacturer culture on these headfi forum threads is really peculiar (when one is not such a "fanboy" oneself). The many lightweight posters who express genuine concerns/issues on this thread, over hundreds of pages, are not always helped, but rather sometimes/too often silenced by biased and aggressively self-assured heavy posters (or else one gets into silly disputes like now, when the former dare repeat his/her concerns - that is just ridiculous).
I do not see how denying the problems brought up by some users on this thread helps anything.
Anyhow, to answer to Musicheaven's comments:
!) I do not have to "dispute" anything; just because you (or anyone) claim(s) that something works, does not mean that it works. I just described one thing that doesn't work and explained how I managed to solve it for my own device, and am not 'daring' to "dispute" some holy cow's infallibility or someone's papal bull. So, back to the album art: The embedded art (before I solved the issue with "Folder.jpg" files in every folder) did not show up, neither in the menu selection nor in "my music". (But they did show up on e.g. VLC when inserting the card in a PC.)
2) If you had actually read my text a couple of posts above, you'd have seen that I did still have the embedded album art not working even after I did all possible forms of tag editing and filename editing down to the most minimalistic and conservative possible formats. So the cause of that specific problem does not lie there.
So, embedded art in FLAC files works perfect for some people? - good for them. But it does not work for everyone (and once again, denial never helps, except maybe in matters of faith). On the other hand, the "Folder.jpg" approach (unless one uses OTG as geagle described) seems to work flawless (unless I forgot someone else's post).
But the most important point I wanted to bring to this thread in my original post today is anyway not about album art. It is that, IMHO, the FAQ should mention very clearly that filenames have to be reduced to a really small size, of [how many?] characters. Cleaning up one's tags again and again, and any other steps advised on this thread, will not help if the filenames are not first all drastically downsized. That is even more dramatically the case since FW 1.2.6, as otherwise the DX50 just doesn't scan your cards at all anymore...
So @ people who still have problems, you should really start with shortening all the filenames, and then see how far you are with the scanning issues.