13.37/x86_64: Xfce4 Shutdown Issue

   Something I did while getting NetworkManager running must have affected
the xfce4 session manager. Now, when I click on the 'quit' icon on the
panel, instead of seeing the icon menu of options the display partially
clears then hangs. The power button needs to be quickly pressed and released
and the machine then proceeds to halt. The display shows a linefeed rather
than a newline (each printed line is offset to the right), but I don't see
a session manager error as I did when there was a typo in /etc/rc.d/rc.M.

   I'd like suggestions on where to start looking for the cause of this new
issue.

TIA,

Rich