Playing youtube videos in iPhone safari

One of the features of iPhone OS 3.0 release is that you can play YouTube videos from iPhone safari. However you for a few weeks since I upgraded to OS 3.0, I was unable to play videos directly from Safari. I found the reason why. If you disable YouTube through the "Restrictions" option in the General settings, YouTube video's wont play from iPhone safari either. With the YouTube restriction on, you will only see a crossed out Play icon in iPhone safari. Hope this helps people facing the same problem.