How to bake several objects into one lightmap with beast?

Hey guys! I have several objects shared a same material, which means they can be drawn in one draw call. But when I bake lightmaps for them, each object is baked into one lightmap, now they can't be drawn in one draw call because of the different lightmap. How can I bake the objects shared the same material into one lightmap? Any clue will be helpful?

PS: Beast_Helper is solution which can merge lightmaps, but it doesn't work well. Anyone use it to merge lightmaps successfully will be helpful? Here is the link: http://forum.unity3d.com/threads/62095-RELEASE-Beast-Helper!-Don-t-lose-old-maps-anymore!