I posted a little while back about migrating Drupal (specifically Drupal 5) with CiviCRM. I said to edit the config backend entry in the crm_domain table. Well I was wrong and boy was I. This is serialized data which should never be edited manually, The site worked but when going into the CiviCRM backend it was incredibly slow and almost painful to use for the client. So the correct way to do this would be to just delete all the information in that box and let it recreate all the info itself. This took multiple days of headaches but hopefully this helps. This would really only apply to migrating sites that do not use the same directory structure.