Hi,
I use the following code

HTML Code:
<div class="msg" >
    <div class="x-box-tl">
        <div class="x-box-tr">
            <div class="x-box-tc">
            </div>
        </div>
    </div>
    <div class="x-box-ml">
        <div class="x-box-mr">
            <div class="x-box-mc">
                <h3>', t, '</h3>', s, '
            </div>
        </div>
    </div>
    <div class="x-box-bl">
        <div class="x-box-br">
            <div class="x-box-bc">
            </div>
        </div>
    </div>
</div>
in order to create message boxes. ('t' and 's' are title and message itself)
This message box has the same default width in almost all browsers (chrome, firefox, etc). This default width is much less than browser window's width.
The incorrect behaviour appears when I try to create the message box in IE9.
Specifically, the message box is stretched to browser window's width if I set document mode to 'IE9 standards'.
Setting other document modes has no effect.
I guess the problem is caused by one of css classes that are used here. (my extjs version is 3.4.0)

Hope this will be fixed
Thanks