Single sign on issue

Hi Guys

We are using Netweaver 7.3 and i have created some webdynpro abap iview and transaction iview. Single sign on is configured. Now every time i logon for the first time and click on some abap webdynpro or transaction iview, i am getting a logon screen as if single sign on is not configured. But when you click on iview again, it displays the relevant screen. Afterwards it works fine without any issue. For the first time logged on it is happening like this.

Please help me resolve this issue.

Thanks and Regards

Madhu N G