I actually don't know why that would be clearing both rows as it's only being applied to the original row (rowNum+1)
although it is prior to pasting the contents even tho it's already copied.
I'd relocate the instruction and only apply it to the new row.
Code:
Private Sub CommandButton1_Click()
Dim rowNum As Integer
'don't let Excel tell me about errors
'On Error Resume Next
'get rowNum to deal with
rowNum = Application.InputBox(Prompt:="Enter Row Number where you want to add a row:", _
Title:="Insert Quote Row", Type:=1)
'incase user closes, cancels or doesn't enter a row number
If rowNum = 0 Then Exit Sub
'prevent screen flash
Application.ScreenUpdating = False
'insert new row
Rows(rowNum).Insert Shift:=xlDown
'copy original row
Rows(rowNum + 1).Copy
'paste formulas of original row
Rows(rowNum).PasteSpecial Paste:=xlFormulas, Operation:=xlNone, _
SkipBlanks:=False, Transpose:=False
'paste formatting of original row
Rows(rowNum).PasteSpecial Paste:=xlPasteFormats
'clear cells with constants in newly inserted row
Cells(rowNum, 1).EntireRow.SpecialCells(xlCellTypeConstants).ClearContents
'stop the marching ants
Application.CutCopyMode = False
'remove selection from entire new row
Range("A" & rowNum).Select
'turn screen updating back on
Application.ScreenUpdating = True
End Sub
Hope that helps.