These are all models that have been POF for some time, and which had most recently been resaved using one of the PCS2 RC builds. So I took all of them, opened them, hit the MOI button, and resaved them (after making backups of all of them of course). I wonder if it's inverted now, if I resave them all again, maybe it will invert them again, thereby making them not inverted?
Edit: Ok, it appears a manual purge is fixing it. Is this a bug then? I'll file a bug report if so. I thought that BSP was supposed to be automatically purged for any older versions of the exporter, and the program has even led me to believe that's the case, since the Show BSP Debug Info was not selectable for any of these models until I saved them again. So I assumed the BSP had already been purged. Now it seems it either wasn't, or wasn't done properly. I don't mind manual purging, but I didn't think it was necessary any longer.