You're very welcome.
(I appreciate points for helpful or correct answers.)
I'm still thinking you have an igroup problem here.
I think the igroup that the LUNs are mapped to on the NetApp still have the old iqn for the windows host.
You don't mention whether you're trying to use command line or System Manager here.
Nor do you mention where/how the 'NetApp does see the iqn' ?
Clicking 'Quick Connect' in the targets tab won't get you there if the igroup doesn't have the iqn there.
You may wish to take a look at the iSCSI Configuration and Provisioning for Windows Express Guide in NetApp documentation.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff
Independent NetApp Consultant, K&H Research http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, Unitek Education http://www.unitek.com/training/netapp/