Checkbox polling and a test site problem.

I've just tried creating a test site following the instructions here and everything seemed to have worked fine, the front page displays everything it should, but when I try to access a node or log in, I get a 404. Common problem? Any ideas?

Secondly, I'm looking for some sort of advanced polling module (like, I guess, Advanced Poll) that's supported on Drupal 6. My specific problem is that I want to have a list of options (I expect about 50) with checkboxes and allow a user to check up to 10 boxes. Each item they've checked receives a vote, just like a normal radio-button poll. I assume that this isn't possible with the normal Poll module (I've examined it pretty carefully), so is there something else that'll help me do this?

Thanks :)