I am using a rich modalpanel to display a pop up on click of a a4j command button in a base xhtml. The modal panel rendering is handled using a boolean value in showWhenRendered attribute.

Sometimes on click of the commandbutton in the base xhtml even if the boolean value is set to true, the pop up doesnt get rendered.

If I open the same base xhtml in a new browser simulatenously, the pop up gets displayed on button click.

During which case the modal panel pop up wont get displayed and why the same modal panel gets displayed when i launch in a new browser. I dont see any javascript error which may restrict the pop up display.

Please help in debugging.