Draw call increase when update to 5.0.1

Unity Engine
1

i have a scene with lightmap under unity 5.0.0, the draw call is 15.

and i update unity to 5.0.1, the draw call increase to 32.

clean the lighmap and bake again still 32.

is there any thing could cause this?

2

Use the frame debugger to check whats the difference between the two versions