@thomaseo: I see. Please try the following steps.
Install the python-pyside package
Copy the following lines to a file, e.g., /tmp/tray_test.py.
from PySide.QtGui import QApplication, QIcon, QSystemTrayIcon
import sys
app = QApplication(sys.argv)
QIcon.setThemeName('hicolor')
icon = QIcon.fromTheme('insync-normal')
tray = QSystemTrayIcon(icon)
tray.show()
sys.exit(app.exec_())
Run python /tmp/tray_test.py. Check if the Insync tray icon is shown. You might need to kill the process explicitly to stop it.
Run /usr/lib/insync/py /tmp/tray_test.py. Check if the Insync tray icon is shown.