ClassCastExceptions DateChooser

Hi,

I get ClassCastExceptions with following DateChooser functions:

getNextMonthButton();
java.lang.ClassCastException: com.smartgwt.client.widgets.Button cannot be cast to com.smartgwt.client.widgets.IButton
at com.smartgwt.client.widgets.DateChooser.getNextMonthButton(DateChooser.java:778)

getPreviousMonthButton();
java.lang.ClassCastException: com.smartgwt.client.widgets.Button cannot be cast to com.smartgwt.client.widgets.IButton
at com.smartgwt.client.widgets.DateChooser.getPreviousMonthButton(DateChooser.java:967)

getNextYearButton();
java.lang.ClassCastException: com.smartgwt.client.widgets.Button cannot be cast to com.smartgwt.client.widgets.IButton
at com.smartgwt.client.widgets.DateChooser.getNextYearButton(DateChooser.java:870)

getPreviousYearButton();
java.lang.ClassCastException: com.smartgwt.client.widgets.Button cannot be cast to com.smartgwt.client.widgets.IButton
at com.smartgwt.client.widgets.DateChooser.getPreviousYearButton(DateChooser.java:981)

Can this please be corrected?

SmartClient version: 4.1 PRO Build vom 10-04-2014

Thanks, Hubert