Your explanations are OK, but it looks like you are not reading the replies properly , the answer is right there for you, by working with the TableSchema property.

Pedro,

Probably there are some methods in SF which will use the TableSchema property of the BO, and in your code you are not updating this property, then it will return the schema of the table which was selected at the time of the BO generation by the BOM.

Like I said before, in your base BO class, simply override that property to return the value of your custom schema, something like this:

Public Overridable ReadOnly Property TableSchema()
     Get
          Return GetCustomSchemaName()
     End Get
End Property
Private Function GetCustomSchemaName() As String
     '-- Add your logic here to return your Schema Name from your source.
     Return "Your Schema Name"
End Function

Or if you want to make is simpler, don't create the GetCustomSchemaName() function and add that logic in the "Get" of the TableSchema property.  If you don't have a base BO, then you will need to do the same for all the BO you create, so it is a best practice to have your own base BO class.

And in your Fill command try to use the propertys of the BO available to you like the TableSchema, so your method may look like this:

Public Sub FillAll()
     Me.FillDataTable("SELECT * FROM " & Me.TableSchema & ".OP_OPER_DET_MO WHERE ORDEN_PRODUCCION IN " & _
" (SELECT ORDEN_PRODUCCION FROM " & Me.TableSchema & ".ORDEN_PRODUCCION WHERE ESTADO='L' ) AND OPERACION = 'GALERA' ORDER BY ORDEN_PRODUCCION")
End Sub

Of course, I have not try the above, it is mean to give you an idea to explore.

I really don't have enough information to give you any direct answers, but maybe some of these ideas will get you going in the right direction depending upon your needs.