I don't like underscores for naming. It's not standard C# naming convention either.

Is there a way to turn off underscores and use automatic properties?

Using .net 4.5 Fluent NHibernate generated code.

Could you please give us an example? For instance: what is the column name in the DB, what is the mapped field name in your LLBLGenPro model? and What is the resulting name on the generated code?

If you go to Project->Settings->Element name construction, there are options to enforce pascal casing and remove underscores from element names. The entity field names should be the ones used to generate the code.