custom attributes problem in comaare table

There is a problem on showing of custom attributes in compare table. When I create an attribute on page of any product, the value of attribute isn’t shown in compare table and the description of attribute is shown alone without input value.

But when i create attribute in main menu of products, related value is shown in compare table. But the problem is this that when we have many vendor with many products, we cant create attributes in main menu in order to prevent vendors from confusion in different attributes from different vendor with different products. Thus we have to define attribute of any product is his related page.

Please help.
Thanks