[radigast]

It looks like there actually was a file called poster with no extension.  This file was not visible in the rlcone mount until a force refresh was enabled.  The root culprit seems to be the artwork scanner that processed the files.  For some reason, it created a picture file with no extension.  I have since removed this rogue file and ensured that all sets have their artwork named correctly.  The scan has run successfully, and, thanks to texturecache.py, I was able to figure out the problems this scanner was creating in my well-groomed artwork.

I have also discovered that there are many illegal characters in my filenames too.  Valid foreign characters with various accents and whatnot...but, I have also needed to clean these up too.