Is there the potential for confusion in that Xara Xtreme Pro and Xara Xtreme Pro 3.2 are different products and have different serial numbers? The number for one won't work in the other. Their serial numbers take the form XXP-nnnn-nnnn-nnnn and P32-nnnn-nnnn-nnnn respectively.

One possible scenario is that Xara have supplied you with the correct serial number but the wrong CD (mixing up Pro and Pro 3.2 one way or the other): there have been a few reports of human error when packing the envelopes in preparation for shipping.