Security Problem

I wrote a program with the Tamino API.
After them, I’ve activatetd the Web Server authetication. Then I protect a node in a TaminoXMLDocument.

If I make querys with the Interaktive Interface or the Tamino Explorer all work fine. The node I had protrected was not send from the tamino.

If I make the same query with my program (Tamino API), I get the full Document.

What’s wrong there?