profile and search issue

http://developer.echonest.com/api/v4/song/search?api_key=&format=json&results=1&title=Best%20I%20Ever%20Had

I can see the id is SOKLJRV13ADC0371BD

then I go to http://developer.echonest.com/api/v4/track/profile?api_key=&format=json&id=SOKLJRV13ADC0371BD&bucket=audio_summary

it returns "audio_summary": {}. Is it possible that some song has no audio summary?

Another issue is from the tutorial: http://developer.echonest.com/api/v4/track/profile?api_key=&format=json&id=TRTLKZV12E5AC92E11&bucket=audio_summary it returns a md5 like this: "audio_md5": "e16bde82eaecd13bde9261b2710aa991" while you cannot do this: http://developer.echonest.com/api/v4/track/profile?api_key=&format=json&md5=e16bde82eaecd13bde9261b2710aa991&bucket=audio_summary

Really new to this, so bear me...