Hi, just ran DDSopt (downloaded for Nexus), using the current ini settings from the wiki, and found that the riverwoodriverwoodtrader01.dds, displays black.
This file is located in the textures\clutter\signage\riverwood folder.
Now if I use the DDSopt_v080pre5b-SSE3 version with it's default ini, the above file is not black.
So there seems to be a difference in how each version is processing the files.