DP8.1 Ipc invalid hostname or ip address

Hi, We have the following environment:

Cell manager - windows 2008 r2, running DP 8.1

Client - Linux Centos 6.5, with installed disk agent. 

The client was successfully imported into the cell. The issue is that when we try to expand its objects from "Backup Tab" the following error pop's up:

"ipc invalid hostname or ip address" - screenshot attached

Also when we try to start the backup it fails with the following error:

[Critical] From: BDA-NET@client3.domain.com "client3.domain.com [/CONFIGURATION]"  Time: 6/2/2014 12:25:02 AM  Cannot connect to Media Agent on system cellserver1.domain.com, port 56324 (IPC Invalid Hostname or IP Address) => aborting.

We have Successfull ping and telnet on port 5555, via IP and FQDN between the client and the cell.

Any assistance identifying the issue will be well appreciated. Thank you in advance!