Cash machine was April 4. It proves nothing but that he might have needed big cash for a big trip, maybe to buy untraceble air tickets under a false name...
You are quite correct. The Tribune story is very misleading - it implies they have ATM pictures of Atta in Florida around April 9. In fact the only picture they have is of Atta withdrawing $8,000 cash in Virginia on April 4. If anything, that would indicate he needed cash for a trip he was about to take.
This whole Atta-Prague business continues to amaze.