Just read an excellent post on migrating print queues: http://blogs.technet.com/b/askperf/archive/2012/04/03/migrating-print-queues-quickly-using-printbrm-configuration-files-and-the-generic-text-only-driver.aspx
Also, there’s a great post on troubleshooting WMI issues using WMIDiag: http://blogs.technet.com/b/askperf/archive/2012/02/03/wmidiag-2-1-is-here.aspx