Kraken Pros not working with Ventrilo

[Counterexample]

Hello All,

I'm using a MacBook Pro - OSX 10.7.5

I recently purchased this pair of Razer Kraken Pros:
http://www.razerzone.com/gaming-audio/razer-kraken-pro

The headset works great on Skype (I have made sure Skype is picking up the headset and not my default, built-in mic). I am unable to use the device in Ventrilo. The device does not seem to be detected at all.

Here's a picture of my headset set-up:
http://**********.us/a/img7/5640/d8g.png
(idk why "image shack" is replaced with "**********" but it won't let me post the link in full. There's no space between the word "image" and the word "shack". Sorry for the inconvenience)

Here's a picture of my Ventrilo set-up:
http://**********.us/a/img812/3281/ghyw.png

Any suggestions?

Thank you.