Opencart Product Adding/Updating Giving Error

hello,
Opencart Verison-1.5.6.4_rc
Using Lexus Theme
I am getting below error when I'm saving the products.

Notice: Undefined index: profile_id in /home/desirediamond/public_html/admin/model/catalog/product.php on line 268Warning: Cannot modify header information - headers already sent by (output started at /home/desirediamond/public_html/admin/index.php:81) in /home/desirediamond/public_html/system/engine/controller.php on line 28Warning: Cannot modify header information - headers already sent by (output started at /home/desirediamond/public_html/admin/index.php:81) in /home/desirediamond/public_html/system/engine/controller.php on line 29