Well, after procrastinating for a week and ripping lots of stitches, I finally looked at the manual and read through all the troubleshooting suggestions. Sounds like something a man would do, doesn't it? Well, everything except the part about actually reading the manual.
The instructions actually warned me against King Tut thread. It said that I should avoid King Tut thread until I was very comfortable and practiced at setting the tension on the machine. It stated that King Tut was hard to set the tension for. It also told me that if I was going to use King Tut thread, that I should use the size 18 needle instead of the size 16 that I usually use.
I know I read all this when I first got the machine, but since I was not using King Tut, I guess I just didn't think about it again.
So anyway......I oiled the machine well, changed out the needle and did some tension setting runs on my practice quilt again. Then I was able to finish the quilt. Finally!
Well, I guess I learned my lesson this time, or not. Will I resort to the manual first next time? Probably not. I told you "I can be such a man" sometimes.