NullReferenceException in JetBrains.BuildServer.NAntLoggers.NAntListenerImp

I have managed to get the Agent to invoke my projects build script however it crashes with the error:

Object reference not set to an instance of an object.
Object reference not set to an instance of an object.
StackTrace:
at JetBrains.BuildServer.NAntLoggers.NAntListenerImpl.TaskFinished(Object sender, BuildEventArgs e)
at JetBrains.BuildServer.NAntLoggers.NAntListener.TaskFinished(Object sender, BuildEventArgs e)
at NAnt.Core.BuildEventHandler.Invoke(Object sender, BuildEventArgs e)
at NAnt.Core.Project.OnTaskFinished(Object sender, BuildEventArgs e)
at NAnt.Core.Task.Execute()
at NAnt.Core.Tasks.LoopTask.ExecuteChildTasks()
at NAnt.Core.Tasks.LoopTask.DoWork(String[] propVals)
at NAnt.Core.Tasks.LoopTask.ExecuteTask()
at NAnt.Core.Task.Execute()
at NAnt.Core.Target.Execute()
at NAnt.Core.Project.Execute(String targetName, Boolean forceDependencies)
at NAnt.Core.Tasks.CallTask.ExecuteTask()
at NAnt.Core.Task.Execute()
at NAnt.Core.Target.Execute()
at NAnt.Core.Project.Execute(String targetName, Boolean forceDependencies)
at NAnt.Core.Project.Execute()
at NAnt.Core.Project.Run()

I will raise a Jira for this but thought someone might have seen this before?

Thanks,
Theo