Is it possible the zoning is not correct on the 5428? Are you using LUN security of some sort? If you issue a show fcswitch command, the last two lines will be the pwwn's of the 5428 that the iscsi initiators will use to access the storage. Make sure these two pwwn's are zoned and also permitted in the array. Then do a show scsirouter and verify the IP address of the windows device is in the access-list to access the storage.
