How can I tell which pa-fe-tx's will work with a 7204vxr with npe-300. I have been told the older cards without handles will not work in vxr's, but cant find anything online to back this up... is it true? Also a side question while im here, could a UBR-7200-I/O-FE be used in a standard 7200 (non vxr) chassis? regards Paul Cairney