WordPress 3.1 was officially released today and one of the great things about this release is that it seems to support the older MYSQL databases that many people, me included, were running WordPress on.
I have upgraded four blogs on my 1 and 1 hosting account to the new WordPress 3.1 and a couple that were running old beta versions of WordPress would not upgrade. The problem was that the version of WordPress after or maybe including WordPress 2.9 would kick the following error:
The update cannot be installed because WordPress 3.1 requires MySQL version 4.1.2 or higher. You are running version 4.0.27
Yes that was a problem for WordPress on 1 and 1 hosting. I did find a messy workaround of creating a new database in MYSQL 5.0 and then backing up from the old database and restoring to the new database and then relinking to the new database.
But this is much better.
To get to the new WordPress 3.1 there should be a banner at the top of the admin screen when you logon to your wordpress installation or else you can go to Updates (right under Dashboard) on the menu bar on the left side of the admin screen.
Remember that it is very important to upgrade and to keep your patch levels up for Wrodpress. One of the features (drawbacks) of almost any widely available blog platform is that there will be a searchable tag of the version that you are at. Hackers will actively look for these unpatched versions that have security flaws and WILL spam your site.