I asked one of the designers to take a look at it, and the following edit was suggested:
In css/template.css around line 370:
.s5_no_custom_bg, #s5_pos_custom_4 {
margin-bottom: 40px;
}
Changing that to 0 will take out half the spacing.
Unfortunately, I'm not sure what you would need to do in order to remove the rest of the gap.