Brian,
Do you have anything hanging from you rear view mirror? I've seen in the past that "stuff" hanging from the mirror will help to pull them off the windshield fairly quickly. We had a couple that wouldn't stay on the window, but there was a small item hanging from it. We took all the stuff off it, and the last time it was put back, it stayed for years..... We used the little 2 tube package with the glass vial and the tube of glue. We also made sure it let it cure at least overnight, or longer, before we reinstalled the mirror on the "button". This also seemed to help.