Hi danwroe,
Sorry for the delayed response. It appears that your page template simply does not provide enough space to fit a slider that is 3 games wide. Game blocks on sliders have a fixed width of 187px. A 3 game slider needs 571px and your containing element is 514px wide. As a first step try a two game slider using the
games_to_show=2
argument in your slider shortcode.
Let me know what happens.
-Mark