Account voucher tax filter
This module adds dynamic filters on sale and purchase vouchers so that sale taxes cannot be used on purchase vouchers and vice versa.
This addon is compatible with OpenERP 6.1. In OpenERP 7.0, the tax selection has been added to the specific views for sale and purchase taxes. For the generic view, the missing filter has been reported as lp:1081097 and a solution has been proposed. Note that you should probably avoid using the generic view to create sale or purchase vouchers anyway due to lp:1080840