In 4.1.3 (and 4.1.1) I'm trying to remove the framing from a window.
In 4.1.0 I successfully used the following:

Code:
Ext.widget('window', {
    width: 300
    , height: 300
    , width: 300
    , frame: true            // never found this to be intuitive, but it's what worked on 4.0.x and 4.1.0
    , shadow: false
    , border: false
    , closable: false
    , html: 'some HTML'
}).show();
Here's an example on JSFiddle. The example by default is using 4.1.0. Switch to 4.1.1 and re-run the example to see the difference.
http://jsfiddle.net/slemmon/9tkAb/