Ok check it out now. Looks like the issue is an IE issue and there is no way to center it without errors. The only solution is to make the block smaller and maker sure images are no smaller than the block. The box is now 400 pixels wide.
I don't have a choice with using IE at work, they block anything we try and add so I'm stuck with IE.
Works fine now for me too. Both at work and at home. For info, I use IE at work and Crazy Browser at home (works the same as firefox).