It's a common problem with Argos, they buy from many places, so the brand names and spec may differ slightly.
They also re-number stock when catalogues change, so something in last years catalogue that's similar to a new product will be shifted across to the new code, despite the fact that it's a different product.
For many lines this isn't a problem, after a £3 toaster is going to be the same inside no matter what name is on the outside, but for technology products this can be an issue, as you mention with the software release.
But at the end of the day, Argos is a box shifter, whether it's a box of toasters or a box of MP3 players, it's all the same to them. If you want a particular product, it's always better to go to a proper shop...