I can tell you exactly why - the homepage at http://www.truckafrica.com/ uses an image map for it's navigation (which is this case is really unnecassary), and search engines can't follow image maps. That is the root of the problem, the engines cannot see beyond that page.

If you email me, I'll rebuild the page for you for nish so that it's compatable, it'll take about ten minutes.

email me at dan@customwebsite.co.uk