Thanks Nils, that's good news the icons are working correctly for you, and I am able to see the world icon in your post. The problem is probably with my browser, even though I am able to see other .png files. I'll try reinstalling, or upgrading, my browswer and see if that helps. One thing I did notice different about the comment boxes in my IE and FF browsers is that in FF there's only one line in the grey title box area which contains (from right to left) person icon, author, title, (space), world icon, email icon, "Author", date and time. However, in IE there are two lines in the grey title box area, and the first line contains (missing) world icon, (missing) email icon, "Author", (space), date and time, and the second line contains person icon, author, and title. So the format for IE and FF are not showing up the same.
Thanks,
Steve