Hello! I've been a long-time Ubuntu user (since 2005), and have only recently begun to actually use Ubuntu One in any meaningful way. While I haven't had too many other real troubles that have prevented me from using the service, this latest issue is insurmountable so far.

On a whim, I decided to take advantage of the 6 months of 20GB space on Ubuntu Music, so I thought I would just go and purchase an album and get the service all set up. So using FireFox, I navigated to the music store, added an album to my cart, and clicked to check out. This then took me to the credit card addition page where I entered my Mastercard information correctly.

Upon selecting the Add Card button at the bottom, I got an error at the top of the list of fields: Invalid Card Details. I tried re-entering the information several different times, including trying with the spaces in the Mastercard number, a space in my postal code, adding the start date (which I have never had to enter on any other forms like Amazon or Paypal), and so on. I always get the same error.

On the credit card entry page, there is no help button which I find incredibly strange and unprofessional. There is no contact number, 1-800 number, or anything, and I find this very disappointing because I am a huge supporter of Ubuntu in general.

Any help would be appreciated.

Also note that I have scoured the internet to no avail ... I have seen one or two similar posts on other forums about AMEX not being properly supported, but I have seen nothing to solve my issue.