Specular issues using Unity lighting macros?

I'm seeing incorrect specular lighting with my custom shader, that makes use of the LightingBlinnPhong macro.

Same code looks fine on every other platform, has anyone seen anything similar on PSM?

(I can post the shader code but it's a thrown-together mess, so I figure it'd be quicker to see if anyone has already noticed a "gotcha" without poring over code)

 

No errors were thrown up, but I'm now almost positive it was related to my incorrect use of alpha that wasn't affecting other platforms, only showing up on Vita. Changed my shader and everything works fine

 

Actually, to elaborate, there is still something different on the Vita build that I am having to take into account to make it match the other platforms. The Unity LightingBlinnPhong function in Lighting.cginc takes the specular alpha into account:

Code (csharp):

1.  
2. c.a = s.Alpha + _LightColor0.a * _SpecColor.a * spec * atten;
3.  

and on the Vita that leads what looks like blown-out specular highlights. I am compensating for this by resetting the alpha in my fragment shader to basically ignore the above calculation.