Can't run cross module Etherchannel, same modules, different HW rev

[d-fillmore]

Hi - I'm trying to create an Etherchannel bundle who's interfaces are spread accross some WS-X4548-GB-RJ45 modules.

This works fine if the HW revision of the modules is roughly the same - it works between cards which are Rev 2.4, but if I then add some ports to the channel on a WS-X4548-GB-RJ45 with HW rev 1.0, the ports stay in suspended mode. If we swap the module for one with a higher HW revision it works

I suspect this is an incompatability of some sort but can't find it documented anywhere

Has anyone else had this or a similar problem?

Or does anyone know where this might be documented on CCO?

Many Thanks in advance

Dom

[glen.grant]

   I haven't heard of anything like that  or seen anything like that on a 4500 .