>To add more information, I discovered that if I let that application sit there for a while, after I attempted to close it, it will eventually close. The timeframe is about 30-120 seconds. At one point, it will be closed for good. So, something is going on in the background that affects that.

Don't know if there's any relationship to what I saw just yesterday...

I had a Large VFP app. that used a smallish .TXT file. When the app. was finished I went to delete the .TXT file and it came up as 'in use by another process' and couldn't be deleted. 10 or so seconds later I could delete it OK.
Now for my first try I had to (after the app. had visibly shut down) first go in Explorer to the correct directory, scroll to find the file, click on it, then hit the Delete key. This itself took some 10-20 seconds.

good luck in your quest.