Thanks! I ran MediaBox from an xterm and got the following. It behaved the same as when I use the application launcher. The first log is the error log from the application. The second is the output of the application.

~Error log
~
~ $ MediaBox > media.log&
~ $ Traceback (most recent call last):
File "/usr/lib/mediabox/mediabox/App.py", line 248, in __load_viewers
viewer = viewerclass(self.__window)
File "/usr/lib/mediabox/viewers/preferences/Preferences.py", line 58, in __init__
self.__add_card(CardMediaRoot(esens, "Media Collection"),
File "/usr/lib/mediabox/viewers/preferences/CardMediaRoot.py", line 25, in __init__
self.__mediaroots = config.mediaroot()
File "/usr/lib/mediabox/mediabox/config.py", line 21, in mediaroot
roots = _CLIENT.get_list(_PREFIX + "mediaroot", gconf.VALUE_STRING) or \
GError: Type mismatch: Expected list, got string

log:
headphones disconnected
clock /usr/lib/mediabox/viewers /usr/lib/mediabox/viewers/clock
image /usr/lib/mediabox/viewers /usr/lib/mediabox/viewers/image
music /usr/lib/mediabox/viewers /usr/lib/mediabox/viewers/music
radio /usr/lib/mediabox/viewers /usr/lib/mediabox/viewers/radio
video /usr/lib/mediabox/viewers /usr/lib/mediabox/viewers/video
preferences /usr/lib/mediabox/viewers /usr/lib/mediabox/viewers/preferences
... handled by _DummyPlayer
... handled by _DummyPlayer
... handled by _DummyPlayer
unknown-stream ... handled by _MPlayer
Starting MPlayer
running
Started Player
Started Player
CTX 1
Playing
.ram ... handled by _OSSOPlayer
Killed Player
Killed Player
CTX 1
seekable: 0
length: 0
has_video: 0
Playing
seekable: 0
length: 0
bitrate: 1000
has_video: 0
Playing
unknown key F5