Ericn84 - When the MIB Browser returns "unsupported", that means that the device returned a "No such name" error code when it was asked for the OID. You can validate that with a sniffer fairly easily.
Darn Cisco for lieing to me saying that the device supports this OID=)
What are we validating?
We've run into the same problem.
We have run packet capture on wireshark and it shows the get-response IF-MIB::ifDescr and the get-next-request IF-MIB::ifDesc over and over.
We ran an snmp get request in MRTG and we got "No such Name" error code.
So, we validated, and we got "No such Name" error code, but what does that mean?