CPA Cache ---- 403 Forbidden

HI,

When I trigger CPA Cache Refresh by

http://<host>:<port>/CPACache/refresh?mode=delta|full

the following message is dislayed

403 Forbidden SAP J2EE Engine/6.40

You are not authorized to view the requested resource.

Details: No details available

-

But I can view the content of the related CPA cache and the history of

cache refreshes in a browser window by :

http://<host>:<port>/CPACache

Why the page shows as forbidden when I trigger CPA Cache ? how to fix this ?

Thanks,

Ram