incompatibility with i18n?

Ooops, i am just a newbie with drupal / php, so please don't blame me if i am wrong - but i have to contradict you.

After your reply i dived a little into the databse layer. There you will find the rule that JOINS must be made using SQL JOIN, not "WHERE" conditions. This rule is violated in "product.module" with the result that i18n is not able to extend the node!

There a two "select" statements (line 1120)

$sql = 'SELECT n.nid, n.title, p.* FROM {node} as n, {ec_product} as p WHERE n.vid = p.vid AND n.status = 1'. tablesort_sql($header);

->
$sql = 'SELECT n.nid, n.title, p.* FROM {node} n INNER JOIN {ec_product} p ON n.vid = p.vid WHERE n.status = 1'. tablesort_sql($header);

and (line 1156)

$sql = 'SELECT * FROM {node} n, {ec_product} p WHERE n.vid = p.vid AND n.status = 1'. tablesort_sql($header);

->
$sql = 'SELECT * FROM {node} n INNER JOIN {ec_product} p ON n.vid = p.vid WHERE n.status = 1'. tablesort_sql($header);

WIth these statements fixed, the page is showing correctly.