[Plugin: NextGEN Gallery] Center thumbnails

I know the code below will center the thumbnails for Firefox, Chrome, etc. But I have yet to find someone who is able to center thumbnails for IE. I really would like them centered for all browsers.

Can someone share the IE specific CSS that I can add on to this?

.ngg-galleryoverview {
text-align: center;
overflow: hidden;
margin-top: 10px;
width: 100%;
clear:both;
display:block;
}
.ngg-gallery-thumbnail-box {
float:none !important;
display: inline-block;
}