Load the URL and click on 1-1 or 1-2. Then, you will see checked radio button.
Strangely Chrome seems to have the same bizarre behavior. Opera doen't. Didn't test IE9.
Comment on attachment 575806 [details] [diff] [review] Patch Please check what IE does. If IE, Gecko and Webkit all have this bug currently, it is possible that we can't change the behavior.
IE9 behaves same as Opera. I guess WebKit has same mistake...