[nsp] GEIP+ flow control question

[Hank Nussbacher]

We have 2 Cisco 7500 routers interconnected via GEIP+ cards that get 
"flow-control is unsupported".  They both run 12.0(25)S2.  One of those 2 
routers has another GEIP+, but it is connected to a Juniper M40 and it 
works properly:

Router A:
GigabitEthernet4/0/0 is up, line protocol is up
   Full-duplex mode, link type is autonegotiation, media type is ZX
   output flow-control is unsupported, input flow-control is unsupported
Gigabit-Ethernet PA(Dual-Wide), 1 ports, FRU: PA-GE=
                 EEPROM format version 4
                 HW rev 0.02, Board revision A0
                 Serial number: 27521023  Part number: 73-4520-03

Router B:
GigabitEthernet4/0/0 is up, line protocol is up
   Full-duplex mode, link type is autonegotiation, media type is SX
   output flow-control is on, input flow-control is on
Gigabit-Ethernet PA(Dual-Wide), 1 ports, FRU: PA-GE=
                 EEPROM format version 4
                 HW rev 0.02, Board revision A0
                 Serial number: 31229403  Part number: 73-4520-03

GigabitEthernet8/0/0 is up, line protocol is up
   Full-duplex mode, link type is autonegotiation, media type is unknown 0
   output flow-control is unsupported, input flow-control is unsupported
Gigabit-Ethernet PA(Dual-Wide), 1 ports, FRU: PA-GE=
                 EEPROM format version 4
                 HW rev 0.02, Board revision A0
                 Serial number: 20759307  Part number: 73-4520-03

What makes the new GE4/0/0 card work with flow control on router B and the
other GE cards don't?

Thanks,
-Hank