I've been having some problems lately since my last Wordpress upgrade, apparently I had too much stuff hacked so the upgrade didn't go as smooth as I thought. So I just reinstalled :).
Followed these steps:
Backup old DB and blog folder
Fresh deployment of wordpress-2.3.1 files
Drop database, create database,
Edit a copy of my backed up SQLdump, and dumped it again in the new DB (only posts, comments, links and data information, no configurations or plugins tables).
It was much easier than I expected, I did not run into any kind of problem at all :D .