on the products_insert.php page, the cart, short and long description initial values are set on the following lines:
cart description, line 522:
$CKEditor_initialValue = "The information you enter here will display on the Shopping Cart page when your customer adds this product to their cart.";
short description, line 563:
$CKEditor_initialValue = "Here you should enter a short description of this product. The information entered here will display on the product catalog page (this field is not used for grid results pages).";
Long description, line 603:
$CKEditor_initialValue = "<p>The long description should be used to detail all the aspects of this product. *This could include the following:</p><ul><li>Technical Specifications</li><li>Instructions</li><li>Product Reviews</li><li>Image gallery of the product (select the 'Insert Photo Gallery' button from the toolbar)</li></ul>";