If I remember right, you have 3 download attemps allowed, so if one goes wrong, you can still try it later. I don't remember if resume is supported by the e-on dowloader.But why would you buy it again? I suppose e-on wouldn't mind sending you a new CD , though maybe not for free, but wouldn't cost as much as buying Infinite, unless of course you need it where you are now.
One more thing, if you go to your account page over at e-on, and have a look at your orders, if you click on your xStream product, does it give you the option to download it?