Quick drop shadow css question for ie8 not working

Just a quick simple question, this css code will not work in ie8 for a drop shadow, any ideas why it wouldn't work?

/* Drop shadow */
-ms-filter: "progid:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=135, Color='#000000')";
filter: progid开发者_C百科:DXImageTransform.Microsoft.Shadow(Strength=4, Direction=135, Color='#000000');
box-shadow: 0px 10px 15px rgba(0, 0, 0, 0.7);
-moz-box-shadow: 0px 10px 15px rgba(0, 0, 0, 0.7);
-o-box-shadow: 0px 10px 15px rgba(0, 0, 0, 0.7);
-webkit-box-shadow: 0px 10px 15px rgba(0, 0, 0, 0.7);

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I am not sure if this is an IE8 bug but if you add a background-color it seems to work as expected.

In Chrome, removing the background-color leaves the drop shadow, but in IE8 the text inherits the drop shadow and looks awful. If you have a solid background you could match the background on the elements you want the drop shadow on. Unfortunately transparent results in the same problem in IE8.

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Specifying a width on the element with the shadow filter fixed a similar issue for me.