Weird message…

Hi All,

Any help would be great. I keep getting the following message when I try to install a particular theme:

Warning: Cannot modify header information – headers already sent by (output started at /homepages/32/d321854622/htdocs/www.contactablogger.com/wordpress/wp-content/themes/discover/functions.php:46) in/homepages/32/d321854622/htdocs/www.contactablogger.com/wordpress/wp-includes/pluggable.php on line 876

What do I do and how do I get around it? ( I really want that theme!)

Ta.