The problem with your solution is that it tries to achieve the transparency with an image file:
#featured .ui-tabs-panel .info{
position:absolute;
bottom:0; left:0;
height:70px;
background: url( images/transparent-bg.png );
Internet Explorer < 7 cannot correctly draw true PNG transparency because it sucks.
The solution on your end is that you are lucky and don t need true image transparency. Instead, you can use the opacity CSS modifier. Search google for "CSS opacity", this is one of the first hits:
http://www.quirksmode.org/css/opacity.html
To make this always work as expected (i.e. the text itself is not transparent) you will have to do additional tricks. E.g. layer a second <div>
element under the real one (not cascading them!), or cascade them and hope you may override opacity in child elements, or ....
That s why in the original version, the trick with transparent image was used.
It clearly shows how badly IE sucks. I would just deprecate it, as I do with my websites.