Could we please talk about that in the Bugreport-Section, because i have renamed and retagged the file in the first Post!
But i think, the reason is definitly not the thumb-folder. The File "Herbert Von KarajanL.jpg" is there, but i think, you mean "C:\ProgramData\Team MediaPortal\MediaPortal\thumbs\Music\Albums\Herbert Von Karajan-xxxL.jpg"! This fle will not be created in this case; Descrption in the Bugreport Section!