Surface lighting model 'MobileBlinnPhong' not found.

I try to create a shader for an iPad3, using the 1 month Pro trial license. I've found several examples on the forum, they are all using this instruction: #pragma surface surf MobileBlinnPhong

But for some reasons it doesn't compile for me. I got the following error message:

Surface lighting model 'MobileBlinnPhong' not found. Available models: BlinnPhong, Lambert

Have I forgotten any setup, or is this MobileBlinnPhong deprecated? My shader works perfectly in the editor with #pragma surface surf BlinnPhong, but then it's just dark on the iPad.