That is a good point. According to cPanel, TCH uses MySQL 4.1.21, whereas my server is running MySQL 5.0.22. I guess the next question would be why TCH hasn't upgraded to MySQL 5?
I tried recreating a backup without complete or extended inserts, and I still get the same errors.
However, I don't think that is the problem at all (not the biggest problem, at any rate). When I try queries such as creating a new database in phpmyadmin, I also get the same access denied error. From all that I have read so far, this leads me to believe that the password used to login to the MySQL server is incorrect from TCH's end, so phpmyadmin cannot login. This doesn't make total sense either (as I can see the databases created in cPanel), but I believe it is something to do with authentication and passwords. Any other ideas?
Edit: Incidentally, there is something else to consider. Is it actually possible to import a database made in MySQL 5 into MySQL 4? If this is not possible, then I think I might just consider creating a new database and forums and starting over from scratch.