From what I've gathered via encyclopedia-google it's a permission denied message basically, the same permission denial that prevents apps-to-sd from working. Generic files *should* be ok tho? ...idk, just grazed the surface, off to explore deeper
I had my old 16GB card from my old DROID2 put in my new RAZR M by the verizon guys at the store. All the apps work, I just can't rearrange my apps and files between the card and the phone storage. Is there something they missed?
I recall a thread where it was discussed that app to SD was not an option on the M. Might not be related to your issue but figured that it was worth mentioning.