I agree that it is not necessarily laziness that causes the procrastination - I certainly don't see myself as a lazy person! I think what stops me writing is fear - that I don't know where to start, don't know what to do, don't think it will be good enough etc...
This happened to me AGAIN last week and up until yesterday didn't know where to start - then I just wrote an outline in bullet points and I realised that maybe I do already know what I want to say! Now I just have the fun job of 'filling out' all my bullet points... But anyway it did help!