Cart takes me to white screen please help!!

I am having a problem with my shopping cart function whenever I try to add something to my cart or delete something from it the system takes me to a white screen. Once I refresh back the item is in the cart but I need to figure out how to fix this white screen problem thank you. Here is what it is saying:
http://mysterydrawer.com/index.php?main_page=product_info&cPath=6_133_136&products_id=13424&action=add_product

Here is the website: http://mysterydrawer.com/

Thank you for your help

Hi.
What changes, or perhaps mods have you newly added?
Look in your cache folder for bug reports and post the latest one here.
See: http://www.zen-cart.com/content.php?124-blank-page

Lol
You also should warn people that this is an ADULT CONTENT SITE!!!
Not cos we are prudes but people could lose their jobs if caught accessing on works computers.

This is what it says and I am so sorry about that I did not even think about that. I hope you did not get in trouble and from now on will make sure to do as you suggested.

[07-Sep-2012 12:41:46] PHP Warning: Cannot modify header information - headers already sent by (output started at /public_html/includes/languages/english/abby_template/header.php:31) in /includes/init_includes/init_templates.php on line 78

Thanks again for your help

Start here:

http://www.zen-cart.com/content.php?129-warning-headers-already-sent

That fixed the problem you both are awesome thank you so much for both of your help and your lightning fast responses.

Thanks again.