Dynamic charting; Diff between exec 2000 and 2007

Oh Wise Ones,

I may have posed this question before, but has anyone else noticed a
difference in the way Excel 2000/Win2000 and Excel 2007/XpPro handle dynamic
charting?
I use application.calculatefull to update my sheet. The numbers in the
columns change, but the chart will not update- it maintains the last number
until i call "refresh sheet" from the dropdown menu that accompanies the
addin that handles the SQL calls. That is with excel 2007. A different
machine running the EXACT same worksheet running excel 2000 updates the chart
continuously while the macro is running. Why the difference? And how can I
replicate "refresh sheet" from the password protected addin?

Thanks,
Mike

My macro in a general module

Dim KeepRefreshing As Boolean
Sub StopRefresh()
Range("A2").Select
With Selection.Interior
.ColorIndex = 3
.Pattern = xlSolid
.PatternColorIndex = xlAutomatic
End With
Range("E2").Select
KeepRefreshing = False
End Sub
Sub AutomaticRefresh()
If KeepRefreshing Then
Application.OnTime Now + TimeValue("00:00:02"), "RefreshThisSheet"
'Application.Caption = Sheets("Lab").Range("A50").Value
End If
End Sub
Sub StartAutoRefresh()
' This function sets it all going, by setting the flag and
' making the initial call to RefreshThisSheet
Range("A2").Select
With Selection.Interior
.ColorIndex = 50
.Pattern = xlSolid
.PatternColorIndex = xlAutomatic
End With
Range("E2").Select
KeepRefreshing = True
RefreshThisSheet
End Sub
Sub RefreshThisSheet()
' This function refreshes the sheet, and then calls the
AutomaticRefresh
' function, which will call it back in a couple of seconds
Application.ScreenUpdating = True
Application.CalculateFull
AutomaticRefresh
End Sub