I have added a filed to sale.order database table through odoo inheritance mechanism. Installed that module and then i checked the sale.order model. I found that custom field.
After that when i removed that custom field from the inherited class, that field is not removed. Even i:
1: Restarted the odoo server
2: Restarted the postgresql server
3 : updated the module list.
4: Re- Installed the module
Performed those operations in both Ubuntu and Windows 7.
I am just tired of solving that issue.
Try to upgrade all modules.
Uninstall your module and check. or else Create a new DB and install your module in which the field is removed. Check if you still can see the field or getting any error in that DB.