If the installer fails to initially log in to the ftp site chosen for an
ftp install (say, because the ftp site has reach its anonymous user limit),
the installer dies with a python traceback.
The proper response is probably to display an error dialog, giving the user
the chance to (a) retry the connection or (b) specify a new ftp site.
A casual user isn't going to know what to do with a python traceback.
See also bug #9612.
This is fixed in the beta version of the installer.