It has been brought to my attention that downloading the album onto a mobile device is causing some people problems.  With iOS this is due to the fact that there's not a dedicated file repository on iPhones.  So, if you're purchasing an album on your mobile device, just make sure you're going to be able to download the album from a laptop or desktop before the link expires.  If not, you might want to wait until you will have access to a computer to download, import to your music player and sync to your device.