when i view source of the confirm page, I seer the folowing code for the item information:
<input type="hidden" name="amount_1" id="amount_1" value="0.01" />
<input type="hidden" name="item_name_1" id="item_name_1" value="" />
<input type="hidden" name="item_number_1" id="item_number_1" value="15" />
<input type="hidden" name="quantity_1" id="quantity_1" value="1" />
the item name value is blank.
paypal requires an item name. Make sure the add to cart button is setting a value for the item name column.