Product Multi Module Useage problem

I am new to Open ERP and have installed to test the features, before taking in real time use.

I have multiple products with variants - Colour, Size.

On searching in the forums, I found out the Product_multi module for this purpose, after installing I'm getting this error

--- Quote
Traceback (most recent call last):
File "netsvc.pyo", line 245, in dispatch
File "netsvc.pyo", line 74, in __call__
File "service\web_services.pyo", line 576, in execute
File "osv\osv.pyo", line 58, in wrapper
File "osv\osv.pyo", line 119, in execute
File "osv\osv.pyo", line 111, in execute_cr
File "osv\orm.pyo", line 1332, in fields_view_get
File "osv\orm.pyo", line 1327, in _inherit_apply_rec
File "osv\orm.pyo", line 1269, in _inherit_apply
AttributeError: Unknown position in inherited view attributes !
--- Unquote

I even tried using a new database with minimal profile and only installed product_multi module, still the same error.

Please advise what is the procedure to use this module.

I am using OpenERP 5.0.10 - All-in-one installer on Win7 prof.