The next version of Google Body will have a separate feedback page for each of these cases:
 Browser supports WebGL, but the user had a problem using Body anyway. We expect people to visit this page if (say) WebGL crashed their system.
 Browser doesn't support WebGL, but the user thinks it should. E.g., we tell them "try downloading Chrome 10, Firefox 4, etc." and the user thinks they already have one of those browsers.
 Browser supports WebGL but initialization failed.
Uploaded a fix for that page. Should go live in a few hours.