I'd take you up on that offer. I'd love to have a third crack at it.
I've had two coding challenges within that last year. One for an internship and one for a full time position (earlier today no reply yet don't expect one). The problem for me is I freeze. As soon as the "testing" type pressure gets put on I go cold and freeze. Then as soon as the test is over I can pull alllllll the information forward. It sucks because I struggle with CS exams too. Every time I have a test I freeze until I'm out of time and as soon as I leave a room it all comes back.