PyDev 2.3 introduced internally Jython 2.2.1. This version has a bug in the sorting routine. A fix existed but was never released in a Jython 2.2.2. The fix was obsolete with Jython 2.5.
See this: http://bugs.jython.org/issue1835099#
I guess no one included the bugfix given there for PyDev.
Thanks for the heads up, will update the Jython version in PyDev.