Well, he ran CCleaner, rebooted, and still cannot access the forum. He says in Internet Explorer he gets a white page, in Firefox he gets an error:
"Database Error: MySQL server has gone away
File: /home/lancedea/public_html/submarinemuseums/forum/Sources/Security.php
Line: 279"
I'm asking for help from the people who know SMF forums much better than I, and for the heck of it I put in a trouble ticket with the web host. I'm just not getting any error messages and without error messages I don't know which way to go.