There are a bunch of songs on my Sansa Fuze and I’ve no idea how they got there - for example, “It’s Yours to Keep” by Loquat, or “Alias and Ehren” by Lillian. I can work out that they were pre-loaded, and that I can delete them if I want. However, they don’t show up when I connect my player to my PC and open the device in Explorer. All my other albums are there. Are they in the firmware?