You know that people don't always know what address they are sending from right?
Your form asks for the sending address. Most people won't be able to predict that.
Unfortunately yes we are aware of this and were at the beginning. I think most of the bitcoin community is aware of this however having this discourages newbies and scam-artists. It is a psychological thing. Our previous plan also involved checking time stamps repeatedly. We are actually changing our address with every purchase and we will be using Bicoin Evolution starting in about 3 hours. If no interest is displayed this month or next month and the lottery lacks sufficient funds to hold an event the funds will be returned to the submitter.