title: Java Unsupported major.minor version 49.0 - where is it coming from?
body: <p>I have downloaded the zxing Google QR code from SVN and used eclipse to edit one of the class files.</p>
  
  <p>I've compiled the changes using ANT and it runs fine locally. When I run it on alive server I get an error:</p>
  
  <pre><code>500 com/google/zxing/client/j2se/MatrixToImageWriter (Unsupported major.minor version 49.0)
  com/google/zxing/client/j2se/MatrixToImageWriter (Unsupported major.minor version 49.0)
  </code></pre>
  
  <p>I have tried compiling it in JDK 1.6 and 1.5 and I get the same error message. Is this something to do with editing the class file in eclipse, and eclipse saving it using a different JVM?</p>
  
  <p>Live server is running 6.0.150</p>