Section 44AD has been modified w.e.f A.Y.2011-12

I am having two types of business i.e. one business is a sole proprietorship and other is professional services (means an insurnace agent or post office agent).

I am having a query that the application of section 44AD is to be applied separately on both the case or the application of section is made on combined considering basis.

As in my case the margin in sole proprietorship is below the required margin and in professional services it quite higher side.

So please provide a proper guidance.