Lighting: Dimmer Pack Issue

I have a dimmer pack that keeps blowing fuses when I add two can lighting fixtures to each channel. When I add just one light, seems to work OK. Unless I overlooked something, the math works out that each channel on the pack should do fine with two of the lights... Could anyone take a look at my equipment and give me a suggestion as to why I am blowing fuses on our dimmer packs?

Dimmer Pack - http://www.chauvetlighting.com/dmx-4.html

Par64 - http://www.musiciansfriend.com/pro-audio/american-dj-par-64-package

Thanks