Thanks for your assistance the map now seems to run as intended. I took the readings from my sat nav and that is how they were displayed.
The other problem is far more tricky to resolve.
I took your advise some weeks ago and removed the cache file but to no avail.
Indeed the deleted file never re-appeared so that I am unable to delete it a second time.
In the guide notes it refers to a folder named en_US but I do not have one. but rather a folder named en_GB. This folder has a configuration folder but with no cache file residing there. One of the previous attachments I sent shows you the "shared" folder and as you can see there is no "WebAssist" folder in that structure.
Any other thoughts?