title: "Comparison method violates its general contract!" when trying to install Eclipse plugin
body: <p>I have following system:</p>
  
  <pre><code>$ cat /etc/redhat-release 
  Scientific Linux release 6.1 (Carbon)
  $ uname -a
  Linux wcmisdlin02.uftmasterad.org 2.6.32-279.9.1.el6.x86_64 #1 SMP Tue Sep 25 14:55:44 CDT 2012 x86_64 x86_64 x86_64 GNU/Linux
  $ 
  </code></pre>
  
  <p>and I have following packages</p>
  
  <pre><code>$ rpm -qa | grep ^eclipse
  eclipse-emf-2.6.0-1.el6.x86_64
  eclipse-svnkit-1.3.0-3.el6.x86_64
  eclipse-swt-3.6.1-6.13.el6.x86_64
  eclipse-rcp-3.6.1-6.13.el6.x86_64
  eclipse-rse-3.2-1.el6.x86_64
  eclipse-jdt-3.6.1-6.13.el6.x86_64
  eclipse-pde-3.6.1-6.13.el6.x86_64
  eclipse-platform-3.6.1-6.13.el6.x86_64
  eclipse-subclipse-1.6.5-6.el6.x86_64
  $
  </code></pre>
  
  <p>Whenever I'm trying to install PDT through Eclipse I'm getting following error:</p>
  
  <pre><code>An error occurred while collecting items to be installed
  session context was:(profile=PlatformProfile, phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
  Comparison method violates its general contract!
  Comparison method violates its general contract!
  </code></pre>
  
  <p><strong>* UPDATE *</strong></p>
  
  <pre><code>$ rpm -qa | grep ^java
  java-1.6.0-openjdk-javadoc-1.6.0.0-1.49.1.11.4.el6_3.x86_64
  java-1.6.0-openjdk-1.6.0.0-1.49.1.11.4.el6_3.x86_64
  java-1.5.0-gcj-1.5.0.0-29.1.el6.x86_64
  java-1.6.0-openjdk-devel-1.6.0.0-1.49.1.11.4.el6_3.x86_64
  java_cup-0.10k-5.el6.x86_64
  java-1.7.0-openjdk-1.7.0.5-2.2.1.el6_3.3.x86_64
  $ 
  </code></pre>
  
  <p>I also found this:</p>
  
  <pre><code>$ sudo grep java-1.7.0 /var/log/yum.log
  Sep 21 12:46:33 Installed: 1:java-1.7.0-openjdk-1.7.0.5-2.2.1.el6_3.3.x86_64
  $ 
  </code></pre>