Currently I become completely crazy with the column "property_account_income_id".
in my database I have installed module Sales and the module Accounting.
When you install accounting, product.py (into Account/Modele) this module add some news column into the table product_template like the column property_account_income_id.
After activate the developer mode, if you check the product form, you can see (in invoice) that you have a relation OneToMany on property_account_income_id into the modele product_template.
If you have a look into Settings->DataBase Stucture->fields: you find too the column property_account_income_id
into the same table product_template. When you update account income (with the Product form) you don't have any problem.
But..., when I use a database tools like 'pgAdmin3' OR 'dbVisualizer', I don't find this column into the table product_template. WHY ?????? Where is this column?????