A newly created grid has its CurrentCell property initialized to Nothing. Pressing [PageDown] or any other key that causes scrolling will crash.

Steps to Reproduce:
1. Launch application
2. Press [PageDown]

 Sub New() 
        InitializeComponent()

        Me.RadVirtualGrid1.ColumnCount = 50
        Me.RadVirtualGrid1.RowCount = 100
        AddHandler Me.RadVirtualGrid1.CellValueNeeded, AddressOf RadVirtualGrid1_CellValueNeeded
    End Sub

    Private Sub RadVirtualGrid1_CellValueNeeded(sender As Object, e As Telerik.WinControls.UI.VirtualGridCellValueNeededEventArgs)
        e.Value = e.ColumnIndex
    End Sub

Workaround: 

Me.RadVirtualGrid1.CurrentCell = New Telerik.WinControls.UI.VirtualGridCellInfo(0, 0, Me.RadVirtualGrid1.MasterViewInfo)