Getting PHP warnings when activating eNewsletter or Comments Plus on a clean WP install

I'm getting the following errors in my WP admin when I activate eNewsletter. I get similar errors when I activate Comments Plus.

Warning: session_start() [function.session-start]: open(/tmp/sess_2dc8ef38d052d03d36712b949767c0c9, O_RDWR) failed: Permission denied (13) in /home/fticusa/public_html/wp-content/plugins/e-newsletter/e-newsletter.php on line 1481

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/fticusa/public_html/wp-content/plugins/e-newsletter/e-newsletter.php:1481) in /home/fticusa/public_html/wp-content/plugins/e-newsletter/e-newsletter.php on line 1481

Warning: Cannot modify header information - headers already sent by (output started at /home/fticusa/public_html/wp-content/plugins/e-newsletter/e-newsletter.php:1481) in /home/fticusa/public_html/wp-includes/option.php on line 563

Warning: Cannot modify header information - headers already sent by (output started at /home/fticusa/public_html/wp-content/plugins/e-newsletter/e-newsletter.php:1481) in /home/fticusa/public_html/wp-includes/option.php on line 564