Using signed certificates via NMSDK

We are getting following error when using signed certifcates with client-ca authentication. Everything works fine when using self signed certificates.

code: AUTHENTICATION_FAILED
message: "Could not connect to the filer with the user creds provided"
detailedMessage: "Error connecting to port 443 of filer mketest. Err: No permission to use \'hostsequiv\' authentication, must be root.."

Any help really appreciated.