[Eclipse] Comparison method violates its general contract error when updating

When installing updates in Eclipse, you may encounter the "Comparison method violates its general contract" error.

This may be related to a known bug in older Eclipse versions when using new JDKs (>6), I encountered it even using a JDK6 with latest Helios though. To fix it, try adding:

-Djava.util.Arrays.useLegacyMergeSort=true

in your eclipse.ini file, after the -vmargs flag, then restart Eclipse and run the update manager again.