title: In manage products, the “inventory” tab is blank
body: <p>In the Admin Panel, when I go to Manage Products, on all individual products, the “Inventory” tab is blank. </p>
  
  <p>When I look at the page code for this control panel page, there’s nothing inside the div:</p>
  
  <pre><code>&lt;div style="" id="product_info_tabs_inventory_content"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>So whatever’s supposed to be loading the inventory data is failing. On the other hand, all the other tabs are showing content correctly.</p>
  
  <p>I’m using Magento Community 1.7.0.2.  I’ve got a couple plugins, but they’re not related to the inventory (e.g. one’s for mailing list, another’s for gift cards)</p>
  
  <p>Is there a particular piece of code I should be looking at to fix this?</p>
  
  <p>I’ve cleared the caches, indexes, and rebuilt the compilation (and turned it off). </p>
  
  <p>As a footnote, now whenever I make a change to to a product, it causes the cache to be invalidated  (the Block HTML to be specific) - but I'm not sure if this is related or if it's a red herring.</p>