If I
1. click on the folder icon "Load image from file" to add posters,
2. select multiple posters and load them all at once,
3. click on the paper clip icon "Use as default" for a poster other than the first one
the setting doesn't hold. When I select a different movie and then go back to the one I just added, I have to re-click on the "Use as default" paper clip icon on the one I want set as the default. Only then will it stay set permanently.
BTW, I only recently realized that you don't have to use the right arrow icon to navigate through your posters. You can just right click on the poster to navigate to the next one. I can't believe it never occured to me to try that.
PVD v0.9.9.19, Windows 7 64-bit