Hey, Keith ...

I don't know what I was doing wrong before or right now, but the fact is, your PowerShell script is working now. The properties for "author" and "subject" are maintained, but I have to run it with a batch file with administrator privileges. I will try an Autohotkey solution so that the script can run automatically as soon as the explorer is closed.

But it would be interesting to know what is causing this behavior of not writing exactly these two properties. Did you find any leads when you went through this?