2 x 40G LAG on ICX7550 100G ports not allowed?

[zotacno]

Hi,

Yesterday I was trying to configure a LACP connection using two QSFP+ DAC cables between a Brocade VDX 6740 and an ICX-7550-24ZP. The VDX was no issue to configure, but on the ICX I ran into issues specifying the port-speed. 

I disabled stacking on the ICX and removed the interfaces 1/2/1 and 1/2/2 as stack ports. Then I created a LAG, no problems there either. However, as soon as I specify the speed at 40G, I get the following errors:

lag VDX dynamic id 10
ports ethe 1/2/1 ethe 1/2/2
port-name "Uplink VDX" ethernet 1/2/1
port-name "Uplink VDX" ethernet 1/2/2
!
SSH@demoswitch(config-lag-if-lg10)#speed-duplex 40g-full
INFO: lg10: 40G Speed is applied on 100G port , ensure 40G optics is present
INFO: 1/2/2: 40G Speed is applied on 100G port , ensure 40G optics is present
INFO: lg10: 40G Speed is applied on 100G port , ensure 40G optics is present
Error: Speed 40G can't be supported for 1/2/2 lag member ports, try least common speed

If I don't specify the speed at all, the link will not come up at all. 
For now I removed one of the interfaces from the LAG, and set it up as a single interface and that works fine at 40G.

Am I missing something?  ICX is running 08.0.95d firmware