Still having problem with formula

here it is:
VB Code:
  1. ActiveCell.Offset(0, 3).Formula = "= SumIf(C12:" & [SunAdd] & ", >0, D12:" & [SunLyAdd] & ")"

what's wrong with it??
I'm having a Run time error 1004
applicatiion-defined or object-defined error

Thnaks