NWZ-S765, How do I select all music files

[you_what]

I use my Walkman for both music and audiobooks. The 'Media Go' program has individual folders for Music and Audiobooks, but the Walkman has a single 'All Songs' folder that contains both my music files and the spoken files. This pretty much kills shuffle stone dead. I can't believe that Sony shipped this player with such a killer fault.

Does anyone have a solution to the problem? The only one I can think of is changing all my music files to the same genre and then select them in the genre folder, but I'd rather not use such a sledgehammer.