Help with VisualHub converting audio tracks

[chicubfan]

I'm using visual hub to convert some mkv videos into mp4's so i can load them onto my iphone. the problem is that the videos have a japanese and english audio track on them. when i convert them it automatically uses the japanese track when i want the english version.

How can I have visualhub use the english instead of the japanese track?

Or can I do something to the resulting mp4 to disable the japanese track?

Thanks.