I had a lot of problems importing our MySQL 4 database into MySQL 5. This blog post told me how to do it right. Then I read here that on Bluehost I needed to activate Ioncube to get our Memberwing subscription plugin to work.
I was able to use the auto-upgrade for all of our plugins and as far as I can tell they all work. Wordpress is up to date and everything seems fine so far! Premium subscribers–PLEASE let me know if you have any trouble logging in. xojessica