We've just seen funny bug similar to CSCsq36972. Portchannel mistakenly treats it's member trunk port mode as dynamic. This port is not allowed to join port-channel and is suspended. But member port is actually non-dynamic.
1471768: Oct 29 2014 11:07:42.507 GMT+6: %EC-SW1_SP-5-CANNOT_BUNDLE2: Gi2/6/9 is not compatible with
Po222 and will be suspended (trunk mode of Gi2/6/9 is dynamic, Po222 is trunk)
interface GigabitEthernet2/6/9
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport nonegotiate
channel-group 222 mode desirable
The differences with aforementioned bug-case are:
1 we were not using "no shut", we just physically unplugged in plugged-in cables.
2 we had Ten mixed with Gig interfaces in one Portchannel and tried to use Gig as a backup in case Ten fails.
So when Ten fails, Gig should automatically unsuspend and join Portchannel. But it was suspended for competely different reason!