Nav Help Contents Tab not showing correctly!

Hello, Has anyone any idea what controls the contents of the “Help Contents Tab”. I have installed MBS Nav 3.70 on a Thinkpad running windows XP. When I open Help from within Navision the “Contents Tab” is filled with the Thinkpad Help contents! However the index tab is correctly filled with the navision help index. The contents are correct for other applications, what’s gone wrong with the Nav Help? Thanks!