Error scanning domain

Hello,

I am trying the eval version to scan our domain and I get the following error:
FAILURE : No response received from workstation. Probably the workstation might be switched off or does not exist.

When I check the log file it says:

[11:35:31:856]|[03-18-2005]|[com.adventnet.servicedesk.asset.discovery.IpUtil]|[INFO]|[27]|: Command String formed is ping -n 3 -w 3000 xxxxxxxx |
[11:35:34:105]|[03-18-2005]|[com.adventnet.servicedesk.asset.discovery.NodeDiscovery]|[INFO]|[27]|: Node : xxxxxxxx is not responding for Ping. Probably the Workstation might be switched off.|

However I can issue the same command (ping -n 3 -w 3000 xxxxxxxx) from command line with success.

What can be the problem?