zl5406 and mstp spanning tree

[snakkes]

We have two 5406, one 12 module and on 6 module,. The 5406 are having  one 8 port 10 GB sfp+ module each and also one 8 port 10 GBE module each. We are using mstp on both zl5406s and  the 10 GBE modules runs 2 lacp trunks between the ISCSI Vlan and the vmware prod vlans. For some reason the trunk on the "left" module, sets the trunk port to blocking. The iscsi vlan are isolated to specific ports and are not related to the other trunk port, so I cant tell where I did wrong here. Vlan 1 is not enabled on the trunk ports.

Any advice would be apprecieted!.

The

[snakkes]

Have to clarify.
Module B
port 1 and 2 untagged with ISCSI vlan id 128.
Port 3 and 4 untagged with vmware prod vlan id's 5,6,7,8.
Port 5 and 6 tagged vlan id 128 LACP trunk to port 5-6 on module A
Port 7 and 8 tagged vmware prod vlans id; 5,6,7,8 to port 7-8 on module A.
Module A:
port 1 and 2 untagged with ISCSI vlan id 128.
Port 3 and 4 untagged with vmware prod vlan id's 5,6,7,8.
Port 5 and 6 tagged vlan id 128 LACP trunk to port 5-6 on module B
Port 7 and 8 tagged vmware prod vlans id; 5,6,7,8 to port 7-8 on module B.
The setup is done like this to isolate the iscsi traffic. The iscsi trunk goes into blocking state on switch A. Im not familiar with lacp, but I am wondering if this is happening because of the tagging of the iscsi trunk.