Blank page errors with login checkout and add to cart

[Dreamwater]

I have been getting blank pages whenever I try to log in, add to cart, and checkout..

I installed the debugger Logging Utility, but am not sureof what it actually means (noob alert) copy of some of the logs below...

Any assistance is much appreciated...

DW

Forgot to add site is http://www.dreamwater.com.au/shop

[05-Feb-2008 18:42:49] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/init_includes/init_templates.php on line 78

[05-Feb-2008 18:42:49] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/functions/functions_general.php on line 44

[05-Feb-2008 18:44:27] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/init_includes/init_templates.php on line 78

[05-Feb-2008 18:44:27] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/functions/functions_general.php on line 44

[05-Feb-2008 18:44:30] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/init_includes/init_templates.php on line 78

[05-Feb-2008 18:44:50] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/init_includes/init_templates.php on line 78

[05-Feb-2008 18:44:50] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/dreamwat/public_html/shop/includes/languages/english.php:1403) in /home/dreamwat/public_html/shop/includes/functions/functions_general.php on line 44