Self-explanitory. Non-flash (HTML 5) video on Youtube does not play correctly in the last couple nightly builds. The video's sound will play; movie stays a black box. Currently running r72284. H.264 video works as it should in Safari 5.0.2.
<rdar://problem/8713401>
I can't reproduce this with nightly r72896. Reporter, can you be more specific?
I can't reproduce it now either. Perhaps the problem was on Youtube's side? The video in question was a Vevo video. (as were the other videos I tried before reporting) I was almost certain these video used to work without flash installed. Now they require flash. I navigated to a user video and it played as it should. Either it got fixed or I did a bad job of bug reduction. Sorry guys.
Thanks for re-testing.