I recently finished a problem and was going to submit a solution. However, I did not know if my solution was unique enough or not so I decided to go ahead and look at the already submitted solutions and see if I could provide anything of merit. Sure enough my solution was unique and I wanted to submit it. However, because I had said I wanted to go ahead and look at the solutions I was not able to submit a solution. I understand that you want to stop people rehashing old solutions but surely it makes more sense to allow people to make sure they solution has merit to it before posting it.