EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object
  at Mono.Debugger.Backends.SingleSteppingEngine.restore_stack (Mono.Debugger.Backends.StackData stack) [0x0001b] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:1275
  at (wrapper remoting-invoke-with-check) Mono.Debugger.Backends.SingleSteppingEngine:restore_stack (Mono.Debugger.Backends.SingleSteppingEngine/StackData)
  at Mono.Debugger.Backends.SingleSteppingEngine+OperationCallback.RestoreStack (Mono.Debugger.Backends.SingleSteppingEngine sse) [0x0000c] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:2783
  at Mono.Debugger.Backends.SingleSteppingEngine+OperationCallback.DoProcessEvent (Mono.Debugger.Backends.SingleSteppingEngine sse, Mono.Debugger.Backends.Inferior inferior, Mono.Debugger.Backends.ChildEvent cevent, Mono.Debugger.TargetEventArgs args) [0x00097] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:2723
  at Mono.Debugger.Backends.SingleSteppingEngine+OperationCompileMethod.DoProcessEvent (Mono.Debugger.Backends.SingleSteppingEngine sse, Mono.Debugger.Backends.Inferior inferior, Mono.Debugger.Backends.ChildEvent cevent, Mono.Debugger.TargetEventArgs args) [0x0000b] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:3221
  at Mono.Debugger.Backends.SingleSteppingEngine+Operation.ProcessEvent (Mono.Debugger.Backends.SingleSteppingEngine sse, Mono.Debugger.Backends.Inferior inferior, Mono.Debugger.Backends.ChildEvent cevent, Mono.Debugger.TargetEventArgs args) [0x00076] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:1900
  at Mono.Debugger.Backends.SingleSteppingEngine+Operation.ProcessEvent (Mono.Debugger.Backends.SingleSteppingEngine sse, Mono.Debugger.Backends.Inferior inferior, Mono.Debugger.Backends.ChildEvent cevent, Mono.Debugger.TargetEventArgs args) [0x0000c] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:1880
  at Mono.Debugger.Backends.SingleSteppingEngine+Operation.ProcessEvent (Mono.Debugger.Backends.SingleSteppingEngine sse, Mono.Debugger.Backends.Inferior inferior, Mono.Debugger.Backends.ChildEvent cevent, Mono.Debugger.TargetEventArgs args, System.Boolean send_result) [0x00000] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:1854
  at Mono.Debugger.Backends.SingleSteppingEngine.ProcessChildEvent (Mono.Debugger.Backends.ChildEvent cevent, Mono.Debugger.TargetEventArgs result) [0x000d5] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:406
  at Mono.Debugger.Backends.SingleSteppingEngine.ProcessChildEvent (Mono.Debugger.Backends.ChildEvent cevent) [0x003f7] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:356
  at Mono.Debugger.Backends.SingleSteppingEngine.ProcessEvent (Int32 status) [0x00175] in /data/build/2006-07-24a/debugger/backends/SingleSteppingEngine.cs:184
  at (wrapper remoting-invoke-with-check) Mono.Debugger.Backends.SingleSteppingEngine:ProcessEvent (int)
  at Mono.Debugger.Backends.ThreadManager.engine_thread_main () [0x000ce] in /data/build/2006-07-24a/debugger/backends/ThreadManager.cs:306