title: sporadic ASP.NET data error: "Cannot find table 0"
body: <p>Having deployed a new build of an ASP.NET site in a production environment, I am logging dozens of data errors every second, almost always with the error "Cannot find table 0."  We use datasets and frequently refer to <code>Table[0]</code>, and while I understand the defensive coding practice of checking the dataset for tables before accessing <code>Table[0]</code>, it's never been a problem in the past.  A certain page will load fine one second, and then be missing one of its data-driven components the next.  Just seeing if this rings a bell for anyone.</p>
  
  <p>More detail: I used a <strong>different build server</strong> this time, and while I imagine the compiler settings are the same on both, I have a hard time thinking that there's a switch that makes 50% of my database calls come back with no tables.  I also <strong>switched the project to VS 2008</strong>, but then reverted all of those changes when I switched back to VS 2005.  I notice that the <strong>built assembly has a new <em>MyLibrary</em>.XmlSerializers.dll</strong>, where it didn't used to, but I also can't imagine that that's causing all the trouble.  (It also doesn't fall down on calls to <em>MyLibrary</em>, or at least no more than any other time.)</p>
  
  <p><strong>Updated to add: I've discovered that the troublesome build is a "Release" build, where the working build was compiled as "Debug".</strong>  Could that explain it?</p>
  
  <p>Rolling back to the build before these changes fixed it.  (Rebooting the SQL Server, the step we tried before that, did not.)</p>
  
  <p>The trouble also seems to be load-based - this cruised through our integration and QA environments without a problem, and even our smoke test environment - the one that points to production data - is fine under light load.</p>
  
  <p>Does this have the distinguishing characteristics of anything you might have seen in the past?</p>