Dave Gilbert recently announced the release of JFreeChart 1.0.8. In my tests, all of the sample code from Visualize Your Oracle Database Data with JFreeChart worked correctly against this new release. This is not very surprising because the 1.0.8 changes sound like mostly fixes to bugs introduced with JFreeChart 1.0.7 changes.
UPDATE: A 1.0.8a (7 December 2007) version of JFreeChart is now available online at http://sourceforge.net/project/showfiles.php?group_id=15494. It appears that this version may have been released to fix the security vulnerability associated with HTML image maps originally discovered and identified by Rapid7.