Alpha blending + HDR problem

I have a particle system in my scene with a particles->alpha blended shader.
If camera has hdr OFF, the render is just fine, if it’s ON, the colors of the particles are all wrong.
Here is a screen from the scene (rendered right) : img1

And here is a screen from the game camera (with HDR, messed up colors) : img2

I’d rather have the HDR option and render alpha blended particles correctly. Is this possible ?

I just had this problem also, I fixed it by editing the shader and after this line

fixed4 col = 2.0f * i.color * _TintColor * tex2D(_MainTex, i.texcoord);

I added
col = clamp(col, 0 ,1);

something to do with the col values wrapping into negatives