Yeah. Been running an old version of WP for years. Decided to upgrade to the highest v2 2.9. Backed up all the files, followed instructions, told to upgrade database, clicked next, nothing happens. Tried it a number of times, nothing happens. Removed the new WP folder and put all backed-up files back. Nice error messages all over the place. Tried a re-upgrade, backed up again, new files ftp-ed, and got the upgrade your database message again. I have now entered recursive hell.
All the topics are closed, and I fear I've made a mistake. 4 years worth of stuff ... so sad. So sad.