When this happens for me, reloading textures doesn't do anything to correct the issue. Even items with a mat-pose and it being re-applied doesn't always solve this little weird bug. The only thing that always works for me is shutting down Poser so it can clear its cache. Manually clearing its "cache" doesn't help me, either, IIRC. (I don't think clearing the cache that way clears "everything.") With other issues similar to this, I've even had to restart the comp, which leads me to believe its could involve a deeper cache issue caused by something that upsets Poser's digestion.

Long ago, I did "fix it" once. And, no, like all useful information gleaned over one's lifetime of fiddling with small, irksome, issues, I don't remember what I did to fix it... :)