Uncaught client side exeption instead of error message pop out

I'm using vaadin 7 alpha 2 , I came through this problem when i have a form layout with some field component like TextField and PopupDateField, when i enter some wrong format date or interger instead of string for textfield, it should show up a error icon and with some error message indicate the format wrong and so on. But it turn out is a Uncaught exception when i mouse over the field. And this only happen to my fields which added in FormLayout. In VerticalLayout it show the correct error message. Anybody experience this? A bug ? Following is my part of code i tried:

// It give uncaught client exeption: 
FormLayout formLayout = new FormLayout();
PopupDateField fromDate = new PopupDateField("Date");
fromDate.setImmediate(true);	
formLayout .addComponent(fromDate );

// Correct behaviour
VerticalLayout vLayout = new VerticalLayout();
PopupDateField fromDate = new PopupDateField("Date");
fromDate.setImmediate(true);			
vLayout .addComponent(fromDate);

Your problem seems to be the same as this known bug: http://dev.vaadin.com/ticket/8794.

Leif Åstrand: Your problem seems to be the same as this known bug: http://dev.vaadin.com/ticket/8794.

Yes, u r right! Is my bad, i dint search thoroughly on trac. I'm sorry for wasting your time, but your reply really gives lot of help to me. Thanks! :*)