Yes... but that would be the easy way out and we wouldnt be programming Micrrosoft products if we settled for that... ;) 

no, actually, I have about a dozen types of logs that contain the same core data, but each log has different sets of property data that would be within the collection.  I would like to avoid defining on specific class for each of the log types.  What I would like to do is have a generic class that contains the core data and then a collection of log entry proprties for the variable stuff.  The collection would contain the property name, ID and value.  When I get my log back I want to create the columns for that log type dynamically, then as I'm populating my rows, assign them to the specific properties within the sub collection.

you are creating your columns like this

dg.Columns.Add(CreateXamTemplateColumn(i, "Hours" & i.ToString()))

the CreateXamTemplateColumn's second parameter takes the property name.  You need to pass just the property name to the method and NOT concatenate it with the index.  You are basically setting your binding expresion to

Binding Periods[0].Hours0

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!

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

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

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)????