SNMP Agent shows interfaces counters in a bgroup 0 bytes in/out - shows sub-intf counters all the same value

I started playing with SNMP monitoring on an SSG140.

I have Ethernet 0/8 in bgroup0/0
bgroup0/0 has an IP address
bgroup0/0.2 is a tagged vlan
bgroup0/0.3 is a tagged vlan
bgroup0/0.100 is a tagged vlan

Ethernet 0/9 daisy-chains around to the back where I have a 16port etherned card in slot 4.

This all hooks to a Cisco 2960s and is working just fine.

HOWEVER, here's the funny part.

doing an SNMPWALK (or SNMPGET) of Ethernet0/8 or 0/9 -- the counters (32 and 64) are both 0.

Sub-Intf's bgroup0/0 and the rest all show traffic -- but the same amounts.

This doesn't seem right.

I realize this is an EOL device -- but it's like no one ever tested the return values in the firmware.

But I thought I'd ask if anyone else has ever seen this? Feels like a bug.