I updated my MacBook to Mavericks, reinstalled Macports and all Python 2.7 modules I usually use. While running Python I get the following messages:
when importing mlab:
from mayavi import lab
(process:1146): Gtk-WARNING **: Locale not supported by C library.
    Using the fallback 'C' locale.
when running a mlab command such as mlab.mesh(), the display window opens, shows no content and freezes.
I don't get this message while importing spectral, but I get it when running view_cube() the display window showing the image cube, freezes but shows the data cube. It seems there is something wrong with Xterm, but I can't figure it out. How can I keep the display window from freezing and get rid of the Gtk-WARNING?
I checked locale and locale -a, but couldn't see anything unusual:
locale: 
locale
LANG=
LC_COLLATE="C"
LC_CTYPE="C"
LC_MESSAGES="C"
LC_MONETARY="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_ALL=
While using OS X Mavericks one has to use: ipython --pylab=wx instead of ipython --pylab=osx to avoid crashing the X11 window. I don't know why this works.
Gtk-WARNING **: Locale not supported by C library. while using several Python modules (mayavi, spectral)