Configuración OpenERP ver 8 (Odoo) -- 2

We have a dedicated server (Ubuntu) running OpenERP 8 (Odoo). The company sells chickens in units and calculates the price in kilograms. When the product is created, the secondary unit of measure is set in "units" and the amount set to "variable" in order to modify according to real weight of every chicken that is sold. However, when it is issued a sale order, we get a "fixed" ratio calculated for our chicken units versus kilograms. In oder words, when we enter for example 20 units of chicken, the systems gives us a fixed 42,340 kilograms, which is according to the ratio given in secondary unit of measure in Sales tab when creating the product. Thus, when we weight the 20 units of chicken and want to enter the 44,200 kilograms into the system, then we have 20,74 units of chicken when we should have only the initial 20 units. This means that the option "variable" for secondary unit of measure is not working properly. Only works as "fixed". THE JOB: The task is to make possible the option to manage either way, kilograms and/or Units independently each time. 20 chickens do not have the same weight as another 20 chickens. Every time there will be a different weight for chickens. We have an average ratio according to chicken size and their respective weight ranges but is not exact and for the system to work properly has to provide the exact weight and exact number of chickens to do the accounting properly. The job includes configuring the reports and forms to print the secondary unit of measure next to the unit of sale. Note: The accounting and Manufacturing modules are also used. The secondary unit of measure is a feature that is already installed in the Odoo standard version and should be working if it is properly configured in Warehouse, Manufacturing and Configuration. We have tried but we don't get it to work. Se cuenta con el sistema OpenERP 8 (Odoo) en un servidor dedicado en Linux Ubuntu. La empresa se dedica a la venta de Pollo utilizando la variable "kg" para contabilizar los ingresos económicos pero también utiliza la variable "unidades" para comercializar sus productos. al crear el Producto, en la pestaña de Ventas, existe la opción de unidad de venta, sin embargo, al definir definir el tipo de unidad como "variable", sigue habiendo una relación fija entre unidad y kilogramo con lo cual no podemos utilizar el módulo de ventas correctamente. El trabajo consiste en lograr que esta función trabaje adecuadamente, permitiendo que podamos crear un presupuesto borrador con la unidad secundaria (unidades) y posteriormente poder agregar el peso verdadero (kilogramos) sin que se modifiquen la cantidad que se quería comprar. Este trabajo incluye la configuración de los reportes para que incluya la unidad de medida secundaria. Los módulos de producción y contabilidad están ligados a las ventas por lo que la unidad secundaria de medida estaría funcionando en estos módulos también. Hemos tratado de configurar la unidad secundaria de manera correcta en los modulos de produccion, almacen y Configuracion general pero no logramos hacerlo funcionar correctamente.