Following a comment here, I have modified the Composite Beam spreadsheet to correct the stage 1 stresses forces in the reinforcement as listed in Columns 6 and 7, when the tensile face is the top.  The output has also been modified to list from top face to bottom (as for the other output), rather than compressive to tension face.  The updated spreadsheet can be downloaded from:

Composite Design Functions

The version posted recently at Stress increments in prestressed concrete beams has also been updated, and can be downloaded from:

Composite Design Functions-Stress Inc