.png images in AssetManager

I was just demoing the a new site I did to my client.

When showing the AssetManager he was unable to see the ‘New Asset’ or
the ‘Remove Asset’ buttons, turns out he was using IE (I don’t know
the version) but was unable to see the .png images.

I see someone mentioned this a while ago:

"> 2) the new-asset.png in /images. I imagine this just got left out

of the extension, but I don’t know how it will get from the
extension to the /images directory."

http://lists.radiantcms.org/pipermail/radiant/2006-November/002527.html

But I didn’t see a resolution, has anyone else experienced this?