Excel 2010 :: Find The Last Used Row?

I am trying to use the code that can find the last used row in particular column.

Here is the code in module1

Code:
Function LastRow(rng As Range)
Dim temp, temp1
Dim col As Range
With Application.Caller.Parent
For Each col In rng.Columns
temp = Cells(Rows.Count, rng.Column).End(xlUp).Row
If temp > temp1 Then temp1 = temp
Next col
End With
LastRow = temp1
End Function
and code in the range

Code:
=LastRow(V12:V300)

My problem is, this code was working nicely but now it only shows ###.

PS I use MS office 2010