User decision step of WorkFlow in SAP CRM Webclient

Hi all

I have WorkFlow with User Decision step in it. An Justification for this User Decision step ismandatory. But when I take a decision in Webclient it allows me to leave task and do not print any text to explain my decision. I can add attachment myself with description of User Decision but I want the system forces user to do that and does not allow to close task without that.

When I work with the same WorkFlow and the same User Decision step in GUI (SBWP transation) it works as expected. And when I choose a decision a popup for text print appear and force me to print a text.

Does anybody know the reason of such different behavior of User Decision step in GUI and WebClient? And how it is possible to make User Decision work in Web the same as in GUI?

Thanks in advance!