Copy cell range to the last empty raw

Hello there,

I am a newbie! I am trying to create a macro that I can execute for each sheet were it copies a cell range to the last empty raw in column A. I have one workbook, Excel 2007, that contain many worksheets (UnitA, UnitB, etc.) I am trying to run the following in each worksheet and I am getting mix results.

Sub EnterRowDown()
'
' EnterRowDown Macro
'
' Keyboard Shortcut: Ctrl+Shift+D
'
    ActiveSheet.Select
    Range("A1048576:I1048576").Select
    Selection.Copy
    Range("A3").Select
    Selection.End(xlDown).Select
    ActiveSheet.Paste
    Application.CutCopyMode = False
End Sub

* Range("A3") are my headers.
* Range("A1048576:I1048576") is the formula and cell format that I wish to copy. All worksheets have the same range and raw/columns location.

What am I missing here?

Thanks in advance!

All the best,

E-