Slideshow Screensaver Does Not Work When External Display Connected

I use a StarTech USB to DVI adapter to connect a display to my MacBook Pro. I also use the Thunderbolt port to connect another display.

Whenever the USB to DVI display is connected, the Slideshow Screensaver just shows a black screen that says "Loading Photos" and never does anything. As soon as the USB to DVI display is disconnected the screen saver works fine without fail.

The other system screensavers work fine when the USB display is attached, its just the slideshow.

Any ideas on this? Its not an end of the world thing, but just kind of confusing.