I usually carry the battlefield keys with me even though that does not seem necessary. Then the stranges thing happened when I entered act 2. I found the first key and then decided that it was time to drop the others. I jumped to the battle field and came back again after some time. I see my keys which I forgot I had thrown there and went to pick them up! And then suddenly I had access to the level 2 and 3!!!! Is that a good bug of some sort??? Naturally I jumped back to the battlefield to check whether they had infact been opened and yes they had!!!