title: Tortoise SVN does not ask for user/pass and fails
body: <p>I installed tortoiseSVN and was able to do a checkout of the dirs/files that are already in the repository (I don't need to authenticate for that)
  When I try to commit changes I get the following error:</p>
  
  <p>Server sent unexpected return value (403 Forbidden) in response to CHECKOUT</p>
  
  <p>I am never asked to enter my user/pass for authentication.</p>
  
  <p>Tried googling it a bit, and found various mentions of this, but no definite answer.
  I talked with the people in charge of the SVN server on our campus, and they claim that everything is OK on the server side...</p>
  
  <p>Any help would be greatly appreciated :)</p>