In case anyone else stumbles into this thread, the error is that dataRequest.newFetchPersonRequest(id); with an id value isn't actually supported despite being part of the OpenSocial 0.7 spec. The methods just aren't implemented... I've not been able to get word if they're going to be...

I read over http://developer.myspace.com/community/myspace/opensocialref.aspx#opensocial.ResponseItem.getErrorMessage and it looks like I should be able to get the error message for why a request fails from the ResponseItem. For example, I make a call and when I get the result back, I've got an error...