When I'm answering a question, and my question is the 3rd or 4th answer, I can't see the original question while I'm typing. I often scroll up to re-read some part of the original question. Sometimes I even paste the question into the answer box as I'm typing, so that it will be right there for me to read.
I suggest that when answering, the position of the question and the answer edit box should always look the way it does for the very first person to answer a question- that is, the question should be directly above the editor. Then after submitting an answer, it would fall to the bottom, just as it currently does.