I recently bought my wife a 2.2ghz Macbook, which shes really happy with. I set up screen sharing the other day, tried it and it worked, great I thought.

Later on though, when I wanted to copy some files over to her drop box, I couldnt connect to her machine and now even screen sharing doesnt work.

Ive checked her security preferences and she has screen and file sharing enabled, I have rights as well... cant see whats wrong for the life of me at the moment.