Unity 5 lightmapping issue.

I have taken a simple scene made of cubes and a single point light. Directional light is not used. Here is a reference image.

Now for baking i have used unity's default lighting settings with a change in baked resolution. I have set it to 5 texels per unit.

Now after baking the result is like this.

Can any one tell me the reason behind this?

I did not face any problem in unity 4 version. I feel they have changed lighting in unity 5.

PS : If this type of question is already asked please provide the link as i have searched and could not find it.