Changing the following variable in the /etc/my.conf file for mysqld appears to get around the problems with mwdumper failing to complete importing of the XML dumps:
set-variable = max_allowed_packet=20M
mwdumper does not always return errors in this case when this value is not set correctly, but mysqld will display errors in this case provided it is invoked from the command line without piping the input to the program. Fedora Core users are advised to review these settings if they encounter problems importing with mwdumper on these platforms.
Jeff