Fuze+ microsd card not recognized?

i tried this Tool (h2testw), its say there are no Errors. i also Format the uSD Card with 32kb Cluster Size, the same error. With the MicroSDHC to USB Adapter the Card works fine. When I Plug the Card with the Fuze+ i get allwas the same Error Message on Fuze. when Connect the Fuze+ to my Computer i can write any Data to this Card there no Problems, but after disconnect from the pc i get this error. i dont know!?! i think this card has no Errors, i think thats the Player! what do you think?