Copied Worksheet With Macros Still References Original Workbook

I have a workbook within which i have a worksheet that contains a lots of macro code (coded by me). As the workbook gets used by various people, i need to copy the worksheet and the macros across to the updated workbook, which doesnt contain the macro worksheet at all.

I have tried to copy it across by clicking on its tab and using the move or copy facility. This copies the sheet across as required. But for some reason, the macros all reference the old workbook. A small bit here for example for some reason opens up the old workbook and then performs the code in the old worksheet:

Sub SelectAll()
For i = 12 To 20
Set curcell = Worksheets("Form Generator").Cells(i, 3)
If curcell = False Then
Cells(i, 3).Value = True
End If
Next i
End Sub

As curcell is equal to worksheets...() i would have expected it to use the local worksheet, ie the one that the macro is attached to. So why is excel proactively hunting out the old workbook and sheet? is the method i used to copy across the sheet with the macros incorrect? If so, how should i go about it?