Dear Clay,
Thank you again for your help with my e-mail difficulty. I haven't experienced the problem with validation you are describing, but I am wondering if it might be related to the e-mail difficulty.
After troubleshooting for a while and adjusting just about every setting I could think of, one simple possibility came to me. Yahoo was not accepting the MOODLE e-mails. They weren't going into the Spam or Trash folders. They were just gone. I found that the receiver (my sample student account) used Hotmail, it came through fine. That led me to the idea of going to Yahoo's e-mail filter and having the filter send any e-mails from the no reply address straight to the inbox. I've asked my students to do this. With 350 students, that takes 350 people doing something.
There may be another way inside MOODLE, but in a pinch this seems to work.
I hope this will be helpful.
Best wishes,
John