FULL PRODUCT VERSION :
java version "1.6.0_0"
OpenJDK Runtime Environment (IcedTea6 1.6.1) (6b16-1.6.1-3ubuntu1)
OpenJDK 64-Bit Server VM (build 14.0-b16, mixed mode)


A DESCRIPTION OF THE PROBLEM :
The system tray is unusable with OpenJDK in Linux because XToolkit.java source code checks for Metacity or KWin window manager instead of really looking for an available system tray.
Code from OpenJDK6 b17 for the method is:
    public boolean isTraySupported() {
        int wm = XWM.getWMID();
        if (wm == XWM.METACITY_WM || wm == XWM.KDE2_WM)
        {
            return true;
        }
        return false;
    }


This bug described is here:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6438179

and was fixed in JDK6 update 10 and OpenJDK7, but not in OpenJDK6.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Ubuntu Karmic 9.10 with OpenJDK installed and Compiz, call SystemTray.isSupported()


REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
none - use JDK6 update 10 or higher, not OpenJDK

Release Regression From : 6u16
The above release value was the last known release where this
bug was not reproducible. Since then there has been a regression.