title: I can read but not set cookies in my rails app
body: <p>It's the weirdest thing. When I ran the Rails WEBrick debugger yesterday I could do things like</p>
  
  <pre><code>cookies[uid] = s.session_id
  </code></pre>
  
  <p>where 'uid' is a passed argument that has a user id in it, and then expect</p>
  
  <pre><code>cookies[uid]
  </code></pre>
  
  <p>to give me back, say: </p>
  
  <pre><code>29b93443d9ec18168a26e1ab12957b0dd0b799ff
  </code></pre>
  
  <p>Today, I always get back 'nil'. I can read existing values just fine. Any of the keys listed in </p>
  
  <pre><code>cookies.keys
  </code></pre>
  
  <p>work just fine.</p>
  
  <p>Does anyone have a possible explanation for this behavior. It is very maddening, and a Google search hasn't yielded an answer.</p>