Cannot modify header information

[sltech8]

Have the following error when "buy it now, my account, checkout or add to cart" is clicked.

 

Headers already sent by (output started at /home/heely25/public_html/store/includes/languages/english.php:340) in /home/heely25/public_html/store/includes/functions/general.php on line 29

 

Been trying to fix it for the last 24hours solid, please help anybody!!!! :'(

[sltech8]

Its ok I found it thanks to a thread further down, regarding an extra empty line of "whitespace" in my english.php file. :D