Originally Posted by RMac
Album art only works with CDs (and only if that CD is in the Gracenote database). I believe it's even only "store-bought" CDs (won't work with burned CDs from iTunes, for example).
Sounds like it has to do with the way each track's metadata is captured (or rather lost) when songs are converted or ripped. Makes me wonder if this information can be forced into each song file when the data is loaded onto the USB (or burned onto CDs). I may need to futz around in iTunes and check this out.