When you say V5 do you mean Software?
What format are you downloading? I have downloaded the exp format as well as the art formats and they show in my software. However, I do not have your embroidery machine. Can you tell us the steps you are taking to help us help you figure out your issue? We do have many Bernina users here. Perhaps they can help given the steps you are taking.
Have you tried the suggestions in your previous posts? I have a Bernina 440QQE and V6, BUT am running Windows 7 and I am having no problems with any of the sites you have listed. It may be a Windows 8 compatibility. Hopefully someone with Artista Software and Windows 8 will come along with a suggestion or someone more computer savvy than I.