Okay, here are my latest findings:

1. I started Spybot and went into Immunization; the seventy-two Firefox files were again not immunized.

2. I closed Spybot, then I closed Firefox.

3. I restarted Spybot, went to Immunization.

4. The seventy-two files still not immunized, I ran immunization. Very quickly the seventy-two files were immunized. As soon as that happened, the progress bar stopped, approximately one-third of the way across from left to right. However, the "building blocks on the left side continued to run.

5. I tried to close Spybot using both the "X" and File/Exit. Neither worked. I again had to use Task Manager, and as previously, it took two tries to close Spybot, with the second attempt bringing up a "program is not responding" message.

6. I closed Spybot, opened Firefox; after perhaps ten minutes of browsing various sites, I reopened Spybot and checked immunization; as of now, all files, including those related to Firefox, have remained immunized.