getSessionKeys returns null when executed from DSP

Hi,
With the help of PSUtilities ive the code for getSessionKeys in my IntegrationServer. The service when tested from Developer returns results properly. (E.g., keyCount = 3 ; sessionKeys = (StringList)
28063834
$ftest
5039308

But when tried executing from IntegrationServer console it returns me keyCount as 0 and no sessionKeys returned. (Snapshot attached)
The IS is installed in WindowsXP. Version of IS is 7.1

Require timely help.

Thanks
Karpaga