Error from modifying wp-config.php to support the Domain Mapping plugin.

I modified my wp-config.php file - adding the define( 'SUNRISE', 'on' ); statement and I pulled the following set of warning messages which are prohibiting me from accessing WP Admin:

Warning: include_once(/home/causeint/public_html/wp-content/sunrise.php) [function.include-once]: failed to open stream: No such file or directory in /home/causeint/public_html/wp-includes/ms-settings.php on line 18

Warning: include_once() [function.include]: Failed opening '/home/causeint/public_html/wp-content/sunrise.php' for inclusion (include_path='.:disappointed:usr/lib/php:disappointed:usr/local/lib/php') in /home/causeint/public_html/wp-includes/ms-settings.php on line 18

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/causeint/public_html/wp-includes/ms-settings.php:18) in /home/causeint/public_html/wp-content/plugins/wpmu-dev-facebook/lib/external/facebook.php on line 49

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/causeint/public_html/wp-includes/ms-settings.php:18) in /home/causeint/public_html/wp-content/plugins/wpmu-dev-facebook/lib/external/facebook.php on line 49

Warning: Cannot modify header information - headers already sent by (output started at /home/causeint/public_html/wp-includes/ms-settings.php:18) in /home/causeint/public_html/wp-content/plugins/sitewide-privacy-options/sitewide-privacy-options.php on line 557

Warning: Cannot modify header information - headers already sent by (output started at /home/causeint/public_html/wp-includes/ms-settings.php:18) in /home/causeint/public_html/wp-includes/pluggable.php on line 876

I've commented-out the statement for the moment, but I obviously need to resolve the issues. Where do I start?

Thanks ... Michael