errors upon eshop activation

Upon installing and activation eShop, I get the following errors:

Warning: session_start() [function.session-start]: open(/home/users/web/b1408/moo.circlesknitting/cgi-bin/tmp/sess_2d3ffeadf2bc103a06783c387829af0e, O_RDWR) failed: No such file or directory (2) in /hermes/web05/b1408/moo.circlesknitting/wp/wp-content/plugins/eshop/eshop.php on line 48

Warning: session_start() [function.session-start]: Cannot send session cache limiter – headers already sent (output started at /hermes/web05/b1408/moo.circlesknitting/wp/wp-content/plugins/eshop/eshop.php:48) in /hermes/web05/b1408/moo.circlesknitting/wp/wp-content/plugins/eshop/eshop.php on line 48

I have put in a tech help request with my server host, just in case the problem lies there. Is there something I need to do to fix this?

Thank you.