Oh man I'm sorry to hear that.
I've had a problem db / site for a while - driving me mad with log errors, and I speak with a developer who's managing it and said you really have to look at why these are occuring.. it's a 3.013 site we upgraded to 3.1.1. We pinned down the error to the scheduler for one, and the date missing from a later version of the web.config file.
The database some how got corrupted last week, and I had to rebuild it by creating a new one and importing all the tables and store procedures, and luckily it worked, but it kept coming up with this log error, and I was told it was something to do with the installation date not being in the new config file.
I used to use the old web.config file and remove the dnn.config file from the folder install folder, since I don't know about you, but I've got alot of things happening in my web.config file, eg.. my editor, google, inventua urls, large file sizes.. etc, however, was told that's not the way to go - I should be putting / transferring all those things to my release.config file and using the new one because it may have important changes.
However, this is very annoying and I'm glad you've put this here, since obviously for new people who install, it's not an issue, but for those who are upgrading, like many many of us, this is just something that is very frustrating.
I'm sorry you had the problem, but I'm very grateful you took the time to help piece together the nightmare on dnn street that we occasionally have to endure.. so this is really appreciated.
Nina Meiers