Premium Apgrades by having a multisite

Hi everybody,
I just bought the Tracks Theme Upgrades “Background Textures” and “Background images”.
I have a multisite with two blogs for having my blog in 2 languages.
After activating the theme upgrades in one of these blogs i couldn´t activate the upgrades in the other blog.
Hope there is a solution for this – I wouldn´t pay again for the same product.
thanks for advices