Hi, i've just tried extjs and I have to say that's a fantastic work!!!
I just encountered a small problem with both beta1 and beta2 concerning modal dialogs with Ext.LayoutDialog (tested on Firefox 2.0.0.3, but works in IE7).
When I open the dialog, the window is blured (normal) but also the dialog (which poses problem).
To reproduce the problem, just take the example "layout.html" in examples/dialog subdir, edit it, and add after the body tag:
(...)
<body>
<div style="overflow: auto">
(.... the dialog html : visibility:hidden ...)
</div>
</body>
(...)
When you click on the button, the modal dialog appears, but is disabled (blurred). It happens when the dialog is contained in a div with an overflow different from 'visible'