^ That sounds like something I might have done. I'll experiment w/that process.
In the mean time I found this on Head-Fi:
Another annoyance is that every folder is sorted by the date and time the file was written to the internal memory or to the flash card - it will not be sorted by folder name. This is great for making and finding your recordings of various gigs, but not so great when you're trying to use the PCM-M10 as a DAP. A solution to this problem is to periodically copy all of the files you've accumulated on a given flash card off to a folder on your PC, then use the PCM-M10 to format the flash card (while you're at it - just to refresh its sectors), then when you copy the whole lot of it back to the flash card, it will be displayed in the PCM-M10 in the sequence with which the files were added to the card. Joy!