Hello Caetano,
We had already changed the customizing transaction OS27 setting called "Handling Deletion Flag During BOM Explosion" to the value '1 Bill of material deleted' previous to my query.
Even after we do that, the system won't default to the ONLY active BOM for BOM-Display transactions like CS11 and CS03. It stills treats the BOM as one with multiple Alt's
I read the link below which talks about a Note needed for this setting to work. When I talked to our Basis consultants, they said that the note has already been installed in our system.
http://scn.sap.com/docs/DOC-46293
Do you have any other ideas?
Best regards
-Oscar