DrDoc - 7:54 pm on May 8, 2013 (gmt 0)
Welcome to WebmasterWorld!
Is the absence of a proper DOCTYPE in your example accurately reflecting your HTML output, or simply an omission when pasting relevant code in your post?
If you don't have a DOCTYPE, first add that and test again. You will likely start experiencing other problems, but whatever they may be, having a DOCTYPE is better than not having one, as far as consistent rendering goes. Without a DOCTYPE (and a full and correct one, at that) there's no point in even beginning to "fix" issues.