title: Rails form_for not accepting parameters for newly migrated columns
body: <p>I just migrated columns <code>soundcloud_url</code> and <code>image_url</code> to my <code>posts</code> table.  I'm trying to add soundcloud_url and image_url as fields (to submit and create a new post) in _form.html.erb, but everytime I try to submit, I get told that soundcloud_url and image_url can't be blank.  But they're not, what am I doing wrong here?</p>
  
  <p>post.rb</p>
  
  <pre><code>    class Post &lt; ActiveRecord::Base
        validates_presence_of :body, :title, :soundcloud_url, :image_url
      end
  </code></pre>
  
  <p>_form.html.erb</p>
  
  <pre><code>      &lt;div class="field"&gt;
         &lt;%= f.label :title %&gt;&lt;br&gt;
         &lt;%= f.text_field :title, :size =&gt; "80" %&gt;
        &lt;/div&gt;
       &lt;div class="field"&gt;
         &lt;%= f.label :body %&gt;&lt;br&gt;
         &lt;%= f.text_area :body, :rows =&gt; 10, :cols =&gt; 50 %&gt;
       &lt;/div&gt;
       &lt;div class="field"&gt;
         &lt;%= f.label :image_url %&gt;&lt;br&gt;
         &lt;%= f.text_area :image_url, :rows =&gt;"2", :cols =&gt; "50" %&gt;
       &lt;/div&gt;
       &lt;div class="field"&gt;
         &lt;%= f.label :soundcloud_url %&gt;&lt;br&gt;
         &lt;%= f.text_area :soundcloud_url, :rows =&gt;"2", :cols =&gt; "50" %&gt;
       &lt;/div&gt;       
  </code></pre>