I just tried to upgrade from 2.0 to 2.3. My blog is http://www.mathlesstraveled.com. It is being hosted (via an apache virtual host) at wso.williams.edu/~byorgey/wordpress/. Since it's a virtual-hosted domain, however, it should still appear as http://www.mathlesstraveled.com in the browser. This worked fine before the upgrade.
The upgrade seemed to go smoothly and the upgrade.php script reported that the database was upgraded successfully. However, now when I visit http://www.mathlesstraveled.com, it tries to redirect to http://www.mathlesstraveled.com/%7Ebyorgey/wordpress/. This is obviously not correct and gives a file not found error. (I presume that 7E is the hex code for a tilde character.) Both the siteurl and home options in the database are set to http://www.mathlesstraveled.com/. Any help in figuring out where the spurious ~byorgey/wordpress is coming from and how to fix it is greatly appreciated.