DateColumn and Ext.util.Format.date problem in Safari 5.1.1

[chearner]

GridPanel...

<ext:DateColumn Header="Created" DataIndex="Date" Format="dd/MM/Y" />

this renders fine in all browsers except Safari. Safari output looks like "Nan/Nan/0Nan"

If I use a renderer...

<ext:Column DataIndex="Date">
<Renderer Handler="return Ext.util.Format.date(record.data.Date, 'M d, Y');" />
</ext:Column>

the grid panel does not output ANYTHING in Safari, but looks fine in other browsers.

[chearner]

Fix: I was able to fix this by specifying the datatype as Date in my Store, rather than a String.

Weird thing is all browsers, except Safari, were very forgiving and rendered the date properly.