When converting videos with multiple audio tracks, VideoDrive will by default only include the main audio track in the resulting iTunes video. If you wish to include more audio tracks, add the following parameter to the HandBrake parameter field on the Import tab of Preferences:
This will include the first three audio tracks. Add more numbers if necessary.
Note: the info described in this article only applies when selecting HandBrake as the conversion tool on the Conversion tab of Preferences.