Don't have tests to add to test lab in HP ALM 11.52

Hi

I was trying my hands on the new HP ALM 11.52 trail version. I created test cases in the test plan module. After that I went to the Test Lab module to add the tests to a test set. I selected the test set/execution grid tab and hit Select Tests button. On the right pane, under the Test Plan Tree I could see only the Test Subjects but no test under it. Can somebody please shed some light on this issue. I don't see this problem with Version 11.0. 

Regards

Srinivas