Excel problem

Problem I tweeted about:

Column A consists of a data string
Column B contains a value relating to each data string
Column E contains if statement to compare one row against another like this:

=IF(A3614=A3613,"STOP","")

What I need to do is in column E have a formula that returns another
STOP *if* column E contains STOP and column B is not equal to D

My brain is so dead - this should be simple and I'm just not getting it.

I realize there is deduping in Excel 2007 but the client wants the
data in this specific format.

Answer: =IF(E8="STOP",IF(B8<>"D","STOP",""),"")

Thanks to @mrrichardson for helping me out!