[sugar] sugar on FC7 - startup error

[imm]

I've been trying to get suagr running on (yet another) FC7 PC here  
today, but every-time I run it I get the following error (below).
For the record, this is the third box I have tried sugar on (in my  
ongoing saga of doing some tests with TamTam) and this is the only  
one that manifests this fault - the other two both run sugar just  
fine. All boxes are running FC7, and are yum'd up to date, with  
ostensibly the same libraries etc. installed.

Some pointers on what this error is telling me, so I can resolve the  
configuration of this box and get things working, would be very welcome.

Error text in console says:

[devuser at immpc8 sugar-jhbuild]$ ./sugar-jhbuild run
INFO:sugar-emulator:Attempting to find free port for X11 (Xephyr)
INFO:sugar-emulator:  Found free port: #6 (6006)
INFO:sugar-emulator:Starting the Xephyr nested X display on display 6
DEBUG:sugar-emulator:Xephyr command: Xephyr :6 -ac -screen 1200x900 - 
dpi 96
INFO:sugar-emulator:Attempting to launch sugar to replace this  
process: dbus-launch dbus-launch --exit-with-session sugar-shell
Extended Input Devices not yet supported. Impelement it at line 625  
in kinput.c
ERROR:root:Error reading public key: [Errno 2] No such file or  
directory: '/home/devuser/.sugar/default/owner.key.pub'
ERROR:root:Error reading private key: [Errno 2] No such file or  
directory: '/home/devuser/.sugar/default/owner.key'
INFO:root:Hardware manager service not found.
DEBUG:root:NMI service already owned by :1.14, won't claim it.
DEBUG:root:Could not connect to NetworkManager!
Traceback (most recent call last):
   File "/home/Shared/OLPC/sugar-jhbuild/build/bin/sugar-shell", line  
128, in <module>
     main()
   File "/home/Shared/OLPC/sugar-jhbuild/build/bin/sugar-shell", line  
91, in main
     win = intro.IntroWindow()
   File "/home/Shared/OLPC/sugar-jhbuild/build/share/sugar/shell/ 
intro/intro.py", line 196, in __init__
     self._intro_box = _IntroBox()
   File "/home/Shared/OLPC/sugar-jhbuild/build/share/sugar/shell/ 
intro/intro.py", line 128, in __init__
     self._setup_page()
   File "/home/Shared/OLPC/sugar-jhbuild/build/share/sugar/shell/ 
intro/intro.py", line 158, in _setup_page
     self._next_button = CanvasButton(_('Next'), 'go-right')
   File "/home/Shared/OLPC/sugar-jhbuild/build/lib/python2.5/site- 
packages/sugar/graphics/button.py", line 28, in __init__
     icon = Icon(icon_name,icon_size=gtk.ICON_SIZE_BUTTON)
TypeError: __init__() takes exactly 1 non-keyword argument (2 given)

[devuser at immpc8 sugar-jhbuild]$

The shell.log file stored under my home dir shows essentially the  
same...

Where do I look next, please?

-- 
Ian