We have a problem adding multiple identical Adaptec controllers to ASM for management/monitoring.

The situation is that we administer few storages running DSS v6 and are able to add to ASM only one of them at a time; once one of them is successfully added, other can't be producing "Unable to connect to remote system" error message. If first one is deleted from ASM, we are able to successfully add second one and vice versa.

Both hosts have IP addresses assigned which belong to the same subnet, directly connected to the same switch.

Adapters are Adaptec 5805Z
Firmware version is 5.2-0 (17544)
ASM version used is 6.50.00 (18579).
DSS 6.0up45.8101.4622 64bit (first box)
DSS 6.0up45.8102.4622 64bit (second one).

I've contacted Adaptec support but they replied that they do not support Open-E products:

Thank you for your message concerning ASM for the 5805Z controller. I'm sorry, we don't directly support Open-E so we've not tested your specific configuration. We've not have any similar reports under any Linux based OS. I would imagine the agent used in Open-E is not the latest release but I don't know that it could be updated or if the update would resolve your issue.
Please advice where the problem could be and possible solution?

Thanks in advance,
Alexander Khimich