I have 2 fabics, even and odd. The odd fabric works fine, the even fabic has issues when you attach a ds4200 to it. I have confirmed the connectivity basics. I can move the fiber that is plugged into the odd fabric and the DS4200 can be seen in the SVC, put it back to the even fabric and the SVC does not see the storage unit. I have correctly put the wwpn in the zone admin and applied the config(and saved it) When you apply the config in the zone administration, sometimes I get a hiccup in the fabric and any windows device can either loose the connectivty to the san disk or it will drop for a second and reconnect. Sometimes I even see it with my unix box.