Keyboard Focus Breaking with Radio Button Group

It seems simple, but this has been a bit of a headscratcher for me. Given the following (valid xhtml transitional) code: ``` <form action="weird.html"> <label for="test1">T1</label> <input type="radio" id="test1" name="test" value="1" /> <label for="test2">T2</label> <input type="radio" id="test2" name="test" value="2" /> <label for="test3">T3</label> <input type="radio" id="test3" name="test" value="3" /> <label for="test4">T4</label> <input type="radio" id="test4" name="test" value="4" /> <label for="test5">T5</label> <input type="radio" id="test5" name="test" value="5" /> </form> ``` Why is it that I can't tab between radio buttons? This issue seems to be because they all have the same name attribute, but that seems rather counter-intuitive to me as far as accesbility goes. Why does the focus state only get applied to one? Is this because the group is treated as a single element? Are access keys the only non-Javascript solution here?