AutoTests: TestPage is not open error

Hi experts,

One more question re AutoTests: I have scenario which gives error: "TestPage is not open" for the following piece of (pseudo)code:

MyTestPage.TRAP;
MyReport.RUNMODAL;  //this report generates lines on a page and opens this page
BatchNo:= MyTestPage.MyField.VALUE;

But. When I run it with debugger, test is is successful.
The page should open as a result of report run.

I thought maybe the report should take time to generate,
and put SLEEP(10000) before line BatchNo:= MyTestPage.MyField.VALUE,
but it did not help.

Does anyone experienced the same error?

Thanks in advice!