There are two places you can set the age of the items to archive. Using the Auto-Archive settings found under Tools | Options | Other, and on the individual folders. The settings on individual folders will override other Archive settings. There is a button (at least in OLK2007, which is the version on this machine) that will change the individual folder settings to that set in Auto Archive. Check the settings onthe folders you wish to archive to see if they match, and, if not, try that button. Otherwise, you will need to visit each folder, finding the setting under the Properties of the folder.