If you have multiple screens setup - when you go into slide show mode the slide show is displayed on the secondary screen (we assume you have a large screen or TV as the secondary screen) and the controls for the slide show remain on the main screen with the app itself.
However, Fotobounce we have heard reports that the last screen setup (size/boundaries) will be remembered next time you turn on Fotobounce and if you don't have a second screen you could run into issues seeing the window properly.
A work around:
ALT-TAB to the Fotobounce App
ALT-SPACE-X will maximize the screen to the current window and then you can adjust the size to work for the current setup.
Here is a link to some very useful Win 7 keyboard commands:
http://www.shortcutworld.com/en/win/Windows_7.html