Aggregated Etherchannel

Hi,
I have a AIX5.3 P6-520 with 8x1Gb Ethernet ports with possible connections to 2 CISCO 2960 switches.
I can create 8023ad Etherchannels which work correctly with the switches (I have set up for LACP passive and a valid channels)

But can create 2x 8023ad 4Gb Etherchannels with no backups. Then create a 3rd Standard Etherchannel which uses the 1st Etherchannel as it's adapter and the 2nd Etherchannel as it's backup?

I have tried it but keep getting the error

Method error (/usr/lib/methods/cfgech):
0514-040 Error initializing a device into the kernel.
0821-103 : The command /usr/lib/methods/defif failed.
0821-103 : The command /usr/lib/methods/defif failed.

Is it possible or am I missing some extra step?
Thanks

According to IBM, what you are trying is not possible. I had the same idea 2 years ago and IBM came back telling me that I cannot create etherchannels from aggregated adapters. They suggested to aggregate only 3 as primary and use one single adapter as backup. Works fine for us.

Regards
zxmaus

Thanks zxmaus, I guessed that might be the case.