Just a comment to this post....
The upgrade to version 5.0.1 is a very major upgrade!!
Note:- As always with updates of this type please make sure you have a backup prior to upgrade, check for errors carefully on the installation screen (there should be none if all is correct), and validate it is working after the upgrade and that you can see your events.
Please make sure previous DNN framework upgrades have complete successfully. They may not have done if you have AutoUpgrade=False in your web.config. You can check this be running Select * from {databaseOwner}{objectQualifier}Version in Host/SQL. If the last version numbers shown in the Major/Minor/Build columns aren't the version of DNN you think you are on, then you will have a problem. If the DNN upgrades have not completed, the Events upgrades do not run, and it is vital that they do for the upgrade to be succesful. However be assured, your data is not at risk!!
Note also that there is a bug in DNN 5.0.1 which will cause only the first module instance on a portal to be upgraded (DNN-9561). You can upgrade other module instances by going into the module settings and next to the Red banner click the Re-start Upgrade button (Click once only!). The banner will disappear when the update is complete. You may see errors like the one mentioned here - http://www.dotnetnuke.com/Community/Forums/tabid/795/forumid/20/threadid/312804/scope/posts/Default.aspx - prior to clicking the button. Panic not! This is a symptom that the module instance has not been upgraded yet.
The version 5.0.1 upgrade has an incompatability with SQL 2000 databases. Please wait for 5.0.2 before upgrading.
Since the release of 5.01, we have also noted issues upgrading from installations of the module that were orginally installed using versions prior to Events 4.0.0. This is due to 'corruptions' of data and the data model within the database. We have made changes to 5.0.2 which will make this upgrade more reliable. However...
Thanks
Roger