[j-nsp] srx cluster - port channel - cisco switches - esx devices - 12.1x45-d15.5 some virtual machines can't be reached

[pkc_mls]

Hi all,

I'm running a cluster of srx 240 connected to a pair of cisco 2960 
switches with a port channel.

ESXi servers are also connected to the same stack of cisco switches.

vlan 1000 with ip 192.168.100.0 is used for out of band management and 
reachability.

I'm using a dedicated virtual router to route the traffic from this vlan 
to other vlans.

Some virtual machines can be reached but some others can't.

I upgraded today to 12.1X45-D15.5, as I require vpn termination on 
loopback interface,
and I suspect this release to have introduced weirdness into the 
configuration.

Does anyone use a pair of srx devices with this release 12.1X45-D15.5 
have some issues with
this kind of configuration ?

Are there any specific configurations to be used on the port channels 
connected to the srx on the cisco stack ?

Best regards.