DUN Problems with Tomtom Go 510 and Xda Orbit

[Motti]

I have been unable to use tomtom plus services on my Go 510 paired with my Xda Orbit. I have seen many posts about problems with WM6 with DUN having been removed by Microsoft, but my Orbit is running WM5 and I still have problems.

Can anyone shed some light on this topic and how to resolve it?