title: SSRS field scope issue
body: <p>I have an SSRS 2008 R2 report that uses this expression in a table:</p>
  
  <pre><code>=Lookup(Fields!DataSet1Date.Value, Fields!DataSet2Date.Value, Fields!DataSet2Price.Value, "DataSet2")
  </code></pre>
  
  <p>I have 2 data sets and am using the Lookup function to get data from one dataset based on the date in another dataset.</p>
  
  <p>My problem is that this works on machines that I have tried it on, but others are getting errors like this:</p>
  
  <pre><code>Error   1       [rsFieldReference] The Value expression for the text box ‘Col_D2Price’ refers to the field ‘DataSet2Date’.  Report item expressions can only refer to fields within the current dataset scope or, if inside an aggregate, the specified dataset scope.
  Error   2       [rsFieldReference] The Value expression for the text box ‘Col_D2Price’ refers to the field ‘DataSet2Price’.  Report item expressions can only refer to fields within the current dataset scope or, if inside an aggregate, the specified dataset scope. 
  </code></pre>
  
  <p>What other things can we do to troubleshoot this issue?  We are all using the same 2008R2 version.</p>