[c-nsp] Flowcontrol conflict 4506 SupIV / 6509 Sup720

[Jeff Kell]

This may end up a TAC case after I gather more information this morning,
but thought I'd run this by the list in case it rang any bells (or you
had similar configurations)... 

We had a maintenance window last night to push out some IOS upgrades to
our distribution layer, complete with a scheduled reload to try to
minimize downtime.  Everything went well with one notable exception, a
two-port etherchannel trunk between a 4506 and 6509 (that was working
just fine beforehand).  From the 6509 side (which was the side noting
the issue):

Nov 16 21:58:08.727 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface
GigabitEthernet1/22, changed state to up
Nov 16 21:58:08.727 EST: %LINK-3-UPDOWN: Interface Port-channel8,
changed state to up
Nov 16 21:58:08.731 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Port-channel8, changed state to up
Nov 16 21:58:08.743 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface
GigabitEthernet2/43, changed state to up
Nov 16 21:58:08.983 EST: %LINK-3-UPDOWN: Interface Vlan224, changed
state to down
Nov 16 21:58:08.987 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface
Vlan224, changed state to down
Nov 16 21:58:09.147 EST: %LINEPROTO-5-UPDOWN: Line protocol on Interface
GigabitEthernet1/22, changed state to down
Nov 16 21:58:09.175 EST: %LINK-3-UPDOWN: Interface GigabitEthernet1/22,
changed state to down
Nov 16 21:58:08.650 EST: %EC-SP-5-CANNOT_BUNDLE2: Gi1/22 is not
compatible with Gi2/43 and will be suspended (flow control send of
Gi1/22 is desired, Gi2/43 is off)
Nov 16 21:58:08.658 EST: %LINEPROTO-SP-5-UPDOWN: Line protocol on
Interface GigabitEthernet1/22, changed state to down
Nov 16 21:58:08.698 EST: %EC-SP-5-COMPATIBLE: Gi1/22 is compatible with
port-channel members

I've never configured flowcontrol anywhere... and this is the first
issue I've seen.  The 6509 was untouched, the 4506 was
changed/reloaded.  The channel did not come up until I did a flowcontrol
send off (which now does not appear anywhere in the config, making it
even more confusing).

4506 side is the two SupIV supervisor ports.  Was running 12.2(50)SG1
and working, rebooted into 12.2(53)SG1.

6509 blade 1 is a 6724-SFP, blade 2 is a 6748-SFP.

The 6509 has 13 port-channels configured across these two blades and
there have been no issues with any other port-channel.

The 6509 has another port-channel to another 4506 configured practically
the same (different switchport allowed vlans) and had no issues.

Anyone see this before?  Any words of wisdom regarding avoiding
potential flowcontrol issues?

Jeff