IG

any idea whats wrong with my sample or why that Silverlight is throwing that exception that i posted at the top of page 3, (when you click on one of the cells)????

yeah at the moment i am using this and it seems to work 

Private Function CreateXamTemplateColumn(ByVal i As Integer, _
                                             ByVal propName As String) As ColumnBase

        Dim column As New TemplateColumn()

        column.Key = propName & i

        column.HeaderText = String.Format("Period#{0}.{1}", i, propName)

        column.ItemTemplate = XamlReader.Load(CreateColumnTemplate(i, propName))

        column.EditorTemplate = XamlReader.Load(CreateColumnEditTemplate(i, propName))
        ' //edit template  
        Return column
    End Function

Also, generate a unique key for each colum:

Private Function CreateXamTemplateColumn(ByVal i As Integer, _
                                             ByVal propName As String) As ColumnBase

        Dim column As New TemplateColumn()

        column.Key = propName  //*******  Generate Unqiue key **************// string.format("Column{0}", i); or something like that.  Maybe use a random number or somehting, just make it unique.

        column.HeaderText = String.Format("Period#{0}.{1}", i, propName)

        column.ItemTemplate = XamlReader.Load(CreateColumnTemplate(i, propName))

        column.EditorTemplate = XamlReader.Load(CreateColumnEditTemplate(i, propName))
        ' //edit template  
        Return column
    End Function

make sure you are not concatenating anything to the propName parameter.  Actually just remove it all together, and replace the {1} in the string.format method with the Hours property.  Do this with both the item template and edit template methods.

Private Function CreateColumnEditTemplate(ByVal index As Integer) As String

        Dim CellTemp As New StringBuilder()
        CellTemp.Append("<DataTemplate ")
        CellTemp.Append("xmlns='http://schemas.microsoft.com/winfx/")
        CellTemp.Append("2006/xaml/presentation' ")
        CellTemp.Append("xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>")
        CellTemp.Append([String].Format("<TextBox Text='{{Binding Periods[{0}].Hours, Mode=TwoWay}}' TextAlignment='Right'/>", _
                                        index, propertyName))
        CellTemp.Append("</DataTemplate>")

        Return CellTemp.ToString()
    End Function

so i guess based on what you were said earlier about them throwing an error, was it possibly the dup key i error. 

i added the index to "hours" to change the key so i would not throw that exception

i changed it back to test, and just exited the loop after one and it seems to work. 

anythoughts on how to get around this

ALSO, thanks for all the help!