Page Service is NULL

Hi all,

I want to set the Visibility of IViews running in a Portal-Page from Web Dynpro Code. The Web Dynpro Java Application is running in a page.

But when I want to access the Page Service the Instance of IWDPageService is NULL:

IWDPageService pageService = (IWDPageService)WDPortalUtils.getService(WDPortalServiceType.PAGE_SERVICE);

String[] iViews = pageService.getVisibleIViews();

The Version of the Sap Portal is 7.01 SP13.

I also read some other posts and blogs in SCN regarding to my problem but nothing helped.

Is there any configuration in Portal i have to do?

Greeting

Florian