Please take a look at the loop I'm running below...this is taking forever to
execute. It looks pretty simple to me and I'm not sure what the hold up is.
If I cycle through the code in debug mode, every "end with" takes some time,
I assume because the formatting is taking so much time. Does anyone know why
these formatting commands are taking so long to execute?

ws is a worksheet object.
colL colM and colN are collection objects with information pulled from a
table in another application.

For I = 1 To colM.Count
ws.Cells(((I - 1) * 4) + nStartRow, 1) = colL.Item(I)
With ws.Range(Cells(((I - 1) * 4) + nStartRow, 1), Cells(((I - 1) * 4) +
nStartRow + 2, 1))
.Merge
.WrapText = True
.VerticalAlignment = xlTop
End With

With ws.Cells(((I - 1) * 4) + nStartRow, 2)
.Value = colS.Item(I)
.Cells.NumberFormat = "0.0000"
.Cells.HorizontalAlignment = xlCenter
End With

With ws.Cells(((I - 1) * 4) + nStartRow, 3)
.Value = colE.Item(I)
.Cells.NumberFormat = "0.0000"
.Cells.HorizontalAlignment = xlCenter
End With

With ws.Cells(((I - 1) * 4) + nStartRow, 4)
.Value = colM.Item(I)(nSegs)
.Cells.NumberFormat = "0.00"
.Cells.HorizontalAlignment = xlCenter
End With

With ws.Cells(((I - 1) * 4) + nStartRow + 1, 4)
.Value = colN.Item(I)(nSegs)
.Cells.NumberFormat = "0"
.Cells.HorizontalAlignment = xlCenter
End With

For J = 1 To nSegs - 1
With ws.Cells(((I - 1) * 4) + nStartRow, J + 4)
.Value = colM.Item(I)(J)
.Cells.NumberFormat = "0.00"
.Cells.HorizontalAlignment = xlCenter
End With

With ws.Cells(((I - 1) * 4) + nStartRow + 1, J + 4)
.Value = colN.Item(I)(J)
.Cells.NumberFormat = "0"
.Cells.HorizontalAlignment = xlCenter
End With

With ws.Cells(((I - 1) * 4) + nStartRow + 2, J + 4)
.Value = colLMH(I)(J)
.Cells.HorizontalAlignment = xlCenter
End With
Next J

'shrink every fourth row
ws.Cells(((I - 1) * 4) + nStartRow + 3, 1).RowHeight = 6
Next I