Album Washer In-App Purchase Fails

[binar]

I own a Samsung Galaxy Media Player 5.0 and I just bought Winamp Pro 1.3.7 from the Google Play Store, however I am unable to make the in-app purchase for the Album Washer. When I press the "BUY NOW" button it takes me to a new page that displays: Album Washer Nullsoft, INc. at the top. In the middle it displays "Pay With" Mastercard info and also shows a Total of $3.99.

The problem seems to be at the bottom with the "Accept & Buy" button. It seems to be greyed out and pressing on it does nothing.

I would appreciate any help in getting my Album Washer purchase to work. My WinAmp Pro currently shows a lot songs without album art and I would like to change that. Thanks in advance for any help.