Hi Diego,
Yes this was a bug, I have it fixed in my copy so it will be fixed in the next release. As a workaround until then, you can uncheck the Show Offer Detail Link on the Offer. The only real benefit of the -offer.aspx page is if the offer has multiple products. I am currently not using that page for my products but instead show all the details on the -product.aspx page.
Best,
Joe