My guess is that because the xhtml on that page is wrong, its causing the browsers to render it differently.
- semi-colon ( ; ) missing on font-family in the CSS - html tags are missing from top and bottom - auto refresh messge should be in a div - center tags are invalid, div style text-align:center should be used.
Since there is no border color specified in the CSS, the browsers use their default, which is different from each other.