This worked for me – so do this at your own risk.
As all the files have the timestamp of the last time I ran the installer, I assumed that the only thing wrong was that the version number was not changed. I edited the file “DugisGuideViewerZ.toc” and replaced 8.9991 with 8.9992 on both lines at the top of the file.
The installer now gets the right version number as what is currently installed and no longers repeatedly reinstalls the files.
One final assumption being made here is that Dugi will increment the version number when he fixes the problem so that it will overwrite the changes I made when the next update is pushed out.
Cheers,
Chris