Repositioning of comment box

Width and height of my comment box works but strangely its positioning doesn't work. I have tried many other codes for positioning comment box but in all ways the code didn't work. My code is:

 With Range("C" & i)

.ClearComments
.AddComment
 .Comment.Text Text:=strComment
 .Comment.Visible = True
 .Comment.Shape.Width = 400
.Comment.Shape.Height = 100
.Comment.Shape.Top = 255   'This line doesn't work
.Comment.Visible = False

 End With