When I try to add additional files, the message says. "the file xxxxx.xxx could not be copied. It may not exist or is in use by another program.
In “My Computer”, I can only see the maximum size of the internal and external Fuze drives. There are no "properties’ on a right click for the Fuze—only for actual recognized lettered drives.
There are (drive letters & properties) if you switch the player to MSC mode. More people have ‘weird’ or unexplained problems using MTP mode (or worse, Auto Defect) than I can shake a stick it.
The only other thing I can think to tell you is that the card is a class 10.
That may have something to do with it. Class 10 cards are known to be problematic with Sansa players. Class 4 is ideal.