Sharing base type mappings between derived types

Hello,

I've recently found out that it's impossible to share base type mappings of 1 entity between multiple derived types. The case is that I have an entity which is mapped to view & edit models (they are almost the same - that's why base model is extracted).
It would be great if you explain how your .Include<> functionality works and I will be able to extend it, or maybe was I just searching not hard enough and the in-box solution already exists in AutoMapper project?
Thanks hor your help, Artsiom

Short commit history:
- Implement a test as a proof that mapping derived types using base type
  rules is working not properly for multiple derived types