Since upgrading mu OS, I've just switched back to the standard BB Media player after using Flipside. Flipside found the album art for all the albums on my card where it was missing, and they all display ok in Flipside.
When I look at the same albums in the default player, alot of the album art is missing, even if there is a jpg in the albums folder.
If the album has been ripped from cd, the art always shows, and is in the folder with a filename such as AlbumArt{loads of numbers}_large.jpg. If flipside found the art its named artist_album name.jpg. All the jpg's are 200x200 size.
Use a MP3TAG type utility to update your music files. In addition to album art it will automatically update the year, genre, artist, album, track#, etc.
I know my post is a little bit late, but I've searched and searched for a solution to the problem of Windows Media Player, being nice and friendly to album art on the Blackberry Torch using WiFi music sync.
It seems that if you have more than one album under a certain artist in a folder, it sometimes won't show the art, no matter how much finagling you do with Windows Media Player. Also, ITunes has this issue occasionally as well when syncing with the Blackberry through WiFi.
The only solution I've found, is to plug the Blackberry back into desktop manager, and start searching through my files, save a picture of the album art to my computer, rename it to folder and place it in the folder that I want the music to have the album art.
Now, I think WiFi music sync is freakin' awesome, but to truly keep your music files clean on the Torch, I really believe you need to go through them occasionally using windows explorer and the usb chord.