Currently, when you import the revenue, negative numbers will enter into AE at the record level.  HOWEVER, when you click on "Revenue by Type" to make sure your numbers balance, it will not pull any of the records with negative numbers.  This does not allow me to balance my source of information to the imported revenue in AE.  

I have asked this with the AE techs and was told I have to submit it as a suggestion for an enhancement.