Hi jasper,
Thanks for posting you question here. If you mouse over (instead of clicking) the "My Snipes" tab within your account, you should be able to find the "Manage Folders" option among the available choice. Just select that option and you will be taken directly to the page from which you will be able to create or modify your folders.
I hope this helps. If you need any further assistance with your account, please feel free to contact our Customer Support team by mousing over the "Help" tab within your account and selecting the "Contact Support" option.
-Mike