Looks like a bizarre rounding error. As you already have the maximum amount of nesting in your formula in column D (so we can't add an additional rounding function), I would suggest an alternative strategy using a user defined function.

Add the following code in module1

Function ForumSpecial(A As Range, B As Range, C As Range)
If C = "F" Or B = "F" Then
    ForumSpecial = A + 3
ElseIf C = "C" Or B = "C" Then
    ForumSpecial = A + 2
ElseIf C = "K" Or B = "K" Then
    ForumSpecial = A + 1
ElseIf C = "P" Or B = "P" Then
    ForumSpecial = A
End If
End Function
In D32 enter

=ROUND(ForumSpecial(A32,B32,C32),2)

User defined functions are very useful for getting over problems where the level of nesting is maxed out.