Just finished a MySQL 4.0 to 5.0 upgrade on this site, WarriorMsi.org and I thought I would just say…Halllllleeellluuuujjjjaaahhh!
No, seriously…Hhhhaaalllllleeelllllluuuuyaaahhh!
No more needs to be said.
You have to upgrade, as soon as possible, to MySQL 5.0. on ALL your active and inactive domains. Most hosting companies auto give you 4.0 on sign up and some charge for upgrading. My hosting company of 150 websites does not charge for MySQL upgrades. PM me for the company’s name.
Almost all the great add-ins and plug-ins, being developed and being delivered now, that are made for WordPress (and Joomla) are MySQL 5.0 scripts and PHP coding.
For YOUR websites, you need to get Linux servers that are PHP, Ruby and Joomla and MySQL 5.0 compliant, as a “standard” to properly administer a current, in the style and trend, website.
Do it. ASAP.