I finally got my 2339 emails moved from Yahoo to gmail. These emails take up 286 MB (4%) of the 6617 MB google gave me for my email.
Here's part 1 of the journey.
When I started moving them today I was able to move about 100 before things quit working. I shut down ypops and thunderbird and waited a few minutes before starting them up again. It didn't help. I rebooted and that fixed the problem.
So now I'll just have to tell everyone to use my gmail account instead of yahoo.