If you bring up the HalfLivesForm page, enter a value into the "Find:" dialog box and click "Recalculate," after querying, the error below will appear. The error doesn't occur, if you click Recalculate first, then enter the filter value after the results appear.

4/18/2012 4:24:00 PM    Unhandled exception    System.ArgumentNullException: Value cannot be null.
Parameter name: source
   at System.Linq.Enumerable.Cast[TResult](IEnumerable source)
   at pwiz.Common.DataBinding.BindingListView.ResetList(PropertyDescriptorCollection newItemProperties, IEnumerable`1 newItems) in C:\Users\nicksh\svn\pwiz_smallstuff\pwiz\pwiz_tools\Shared\Common\DataBinding\BindingListView.cs:line 266
   at pwiz.Common.DataBinding.BindingListEventHandler.EnsureQueryRunning() in C:\Users\nicksh\svn\pwiz_smallstuff\pwiz\pwiz_tools\Shared\Common\DataBinding\BindingListEventHandler.cs:line 500
Exception caught at:
   at pwiz.Topograph.ui.Program.Application_ThreadExceptionEventHandler(Object sender, ThreadExceptionEventArgs e)
   at System.Windows.Forms.Application.ThreadContext.OnThreadException(Exception t)
   at System.Windows.Forms.Control.InvokeMarshaledCallbacks()
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.DataGridView.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(Form mainForm)
   at pwiz.Topograph.ui.Program.Main()

Not really maintaining Topograph any longer.