Ecommerce integration does not work and throws Warning

Just installed latest Paypernode.mod version (v 1.1 2006/12/10) with Ecommerce 4.7.x-2.1 (Drupal 4.7.2):

bulkupdate feature works sweet as expected. Couldn't make the ecommerce product to work though....created the paytopublish product, setted price, node type (tryed both with poll and book content types), quantity and everything. Bought the product and checked out with my paypal sandbox.

The transaction completes fine, but if i try to add that node with my "peon" user i get an 'access denied' error, and the menu item does not show up too of course.

The only "hint" i can give is this warning i get when i try to edit and submit again my paytopublish product:

user warning: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '0 = '' WHERE vid = 1347' at line 1 query: product_save UPDATE ec_product SET nid = '1110', vid = '1347', pparent = '0', sku = '', price = '3000', is_recurring = '0', price_interval = '0', price_unit = '0', price_cycle = '-1', auto_charge = '0', ptype = 'paypernode', hide_cart_link = '0', 0 = '' WHERE vid = 1347 in /home/public_html/test/includes/database

can anyone give an hand on this? thank you very much