no body can help me?

when I use the version of 1.4.1, the problem is still exist.

my easyui version is 1.3.4
when I click the print button and open a new page(print page),the collapsible button disappear.

my print code is as:
    var newWindow=window.open("print window","_blank");
    var docStr = "<table><tr><td>print error</td></tr></table>";
    newWindow.document.write(docStr);
    newWindow.document.close();
    newWindow.print();

The sub images are the process of the disappear of the collapsible button: