And dropbox is no help either since the phone does not DECRYPT. I'm just backing up encrypted files that at some point, the phone can no longer read.
Recall my opening post, "something" happens and the phone stops being able to read the files, that it had been reading just fine prior. Four times now, and I still don't know what causes this. I can't tie it to software upgrades, booting the phone, mounting via USB cable then switching back to charging, etc. I do all of those things regularly and can't deliberately recreate the issue.
The only thing I've found that absolutely guarantees I can't read the files, is a factory reset on the phone. EVEN THOUGH I AM USING PASSWORD-ONLY encryption option, the phone is not able to read these files after a factory reset. But that is NOT the reason for the four random failures... I just did the first factory reset TODAY on a *working* phone -- as part of trying to find a workaround for when this happens to me again in the future.