Just an update on this,
I have tried all the suggestions, nothing seems to work, mypoi doesn't seem to want to recognise the data in the cfg file, and copy & paste wont work either. I even tried changing the navcore to a non truck one but still no joy.
Updating favourites from the standard maps was simple and strait forward with no problems what so ever.
I am guessing that it must be something to do with the truck maps/ software being a bit of an oddball.
However thanks for all the suggestions, very much appreciated!