folder.jpg not updated when hidden/system attributes are set
Windows Media Player (v12 Windows 7) marks folder.jpg and AlbumArtSmall.jpg with the System and Hidden attributes. Bliss should be able to handle overwriting these.
Ok, I'll take a look into this. Note that multiple artwork in a folder is not currently supported, see http://bliss.uservoice.com/forums/21939-bliss/suggestions/1608043-enforce-zero-one-or-many-separate-cover-art-files