After much work with UAC I have managed to remove the Shield from the Icon so now my application runs without prompting, as I have included in manifest 'AsInvoker'.
Once in a while when I change the Exe File for an upgrade or bug fix, then the prompt comes up again. This happens one in 1000 times.
If I rename the Folder / Exe file then it works fine again. Could someone give an explanation for this odd behaviour.
Please note that my application does not have the word 'Setup or Update' in it. Even if I prefixed '1' to the name the shield disappears.
This has been observed only on Windows Server 2008