Error on first building a subpackage

[Kelet]

Hi, when I pressed "build" for the first time on a subpackage, it gave me this error:

System.NullReferenceException: Object reference not set to an instance of an object

Server stack trace: 
  at MonoDevelop.Ide.Gui.Pad..ctor (MonoDevelop.Ide.Gui.DefaultWorkbench workbench, MonoDevelop.Ide.Codons.PadCodon content) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Workbench.WrapPad (MonoDevelop.Ide.Codons.PadCodon padContent) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Workbench.get_Pads () [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Workbench.GetPad[ErrorListPad] () [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.ProgressMonitorManager.GetBuildProgressMonitor (System.String statusText) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.ProgressMonitorManager.GetBuildProgressMonitor () [0x00000] in <filename unknown>:0 
  at (wrapper managed-to-native) System.Runtime.Remoting.RemotingServices:InternalExecute (System.Reflection.MethodBase,object,object[],object[]&)
  at System.Runtime.Remoting.RemotingServices.InternalExecuteMessage (System.MarshalByRefObject target, IMethodCallMessage reqMsg) [0x00000] in <filename unknown>:0 

Exception rethrown at [0]: 

  at MonoDevelop.Ide.Gui.Pad..ctor (MonoDevelop.Ide.Gui.DefaultWorkbench workbench, MonoDevelop.Ide.Codons.PadCodon content) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Workbench.WrapPad (MonoDevelop.Ide.Codons.PadCodon padContent) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Workbench.get_Pads () [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.Workbench.GetPad[ErrorListPad] () [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.ProgressMonitorManager.GetBuildProgressMonitor (System.String statusText) [0x00000] in <filename unknown>:0 
  at MonoDevelop.Ide.Gui.ProgressMonitorManager.GetBuildProgressMonitor () [0x00000] in <filename unknown>:0 
  at (wrapper managed-to-native) System.Runtime.Remoting.RemotingServices:InternalExecute (System.Reflection.MethodBase,object,object[],object[]&)
  at System.Runtime.Remoting.RemotingServices.InternalExecuteMessage (System.MarshalByRefObject target, IMethodCallMessage reqMsg) [0x00000] in <filename unknown>:0 

It has not happened again, however.

[aBothe]

Must be MD-related, can't have control over this one. Anyway I'd really like to know what a WrapPad is :D