Please forgive the double upload but this info should be here more than a recent post by me...
BTW: The ferromagnetic core mentioned in the patent need not be a ferromagnetic core. It can be a current carrying loop or coil.
IMHO, there is no total cancellation of field interaction. The most pronounced effect is when you polarize the 'shielded' core/loop perpendicular to the field you are shielding from.
Note the coil type suggestions in the patent.
[pdf]http://www.overunityresearch.com/index.php?action=dlattach;topic=47.0;attach=272[/pdf]