Problem Summary: scrgadmprevents the hosting of logical hostnames/shared addresses which belong to a subnet that is different from the subnet of the IPMP (NAFO) group.
Workaround: Use the following form of the scrgadmcommand:
scrgadm -a -j <resource> -t <resource_type> -g <resource_group> -x HostnameList=<logical_hostname> -x NetIfList=<nafogroup>@<nodeid>.
Note that nodenames do not appear to work in the NetIfList; use nodeids, instead.