Excel 2007 : Macro stopped working

Usually I can solve most programming issues by surfing the web, but this one is different.
About 2 months ago my work moved from Office 2003 to Office 2007. My macros worked for a little while but then some stopped. Basically any macro that executes on a selection in a worksheet will now only partially work on the first cell. For instance:

Sub WriteCellFormula()
    Dim temp As String
    For k = 0 To Selection.Rows.Count - 1
        For j = 0 To Selection.Columns.Count - 1
            If ActiveCell.Offset(k, j) <> "" Then
                temp = "=substitute(CONCATENATE(SUBSTITUTE(CELL(""address"",ABCXYZ),""$"",""""),"" = "",SUBSTITUTE(cellformula(LEFT(CELL(""address"",ABCXYZ),LEN(CELL(""address"",ABCXYZ)))),""="","""")),""$"","""")"
                temp = Application.WorksheetFunction.Substitute(temp, "ABCXYZ", ActiveCell.Offset(k, j))
                ActiveCell.Offset(k, j).Formula = temp
                ActiveCell.Offset(k, j).HorizontalAlignment = xlLeft
            End If
        Next j
    Next k
End Sub

This is a macro I have used without hickup for 2+ years, until recently.

Basically this is a complicated way of writing a cell formula in a cell. It was made more complicated because I had to trick it into updating when the referenced cell updated. If I enter "A4" in cell B5 and highlight B5 and run this macro, it will write a cell formula to B5 which will return the cell formula of A4. Fine and good. When the formula in A4 changes, B5 is automatically updated. If you highlight a range (always had to drag to the left and down to work properly), it would do the same for all cells in the range. Now it only does the first cell. The funny thing is it never executes past the line:

ActiveCell.Offset(k, j).Formula = temp

I can put a msgbox after this line and it will never come up, before the line it will.

What gives?

BTW: Function cellformula:

Function CellFormula(loc)
     CellFormula = ActiveSheet.Range(loc).Formula
End Function