If a page creates an Audio element in JS, and tells it to play, then that only works the first time the page is loaded. On Reload, the audio fails to play.
<rdar://problem/6870187>
Created attachment 32247 [details] Patch
http://trac.webkit.org/changeset/45537
It seems that handling such cases with ActiveDOMObject machinery could be more performant than running a long list of checks on each node with a wrapper.