The version I use, from "About PlayMaker", is 1.4.4f3. And Unity version I use is 4.0.0f7.
I am still finding out why this misbehavior occurs.
Don't know if the issue related to the error I get some time after I start to create lots of FSMs and states. The error showing in the debug window like the following.
ArgumentException: An element with the same key already exists in the dictionary.
System.Collections.Generic.Dictionary`2[System.Type,UnityEngine.Object].Add (System.Type key, UnityEngine.Object value) (at /Applications/buildAgent/work/3df08680c6f85295/mcs/class/corlib/System.Collections.Generic/Dictionary.cs:404)
HutongGames.PlayMakerEditor.FsmEditorUtility.BuildActionScriptLookup ()
HutongGames.PlayMakerEditor.FsmEditorUtility.BuildActionsList ()
HutongGames.PlayMakerEditor.FsmEditorUtility.get_Actionslist ()
HutongGames.PlayMakerEditor.ActionSelector.BuildFilteredList ()
HutongGames.PlayMakerEditor.ActionSelector.OnFocus ()
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Applications/buildAgent/work/3df08680c6f85295/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Applications/buildAgent/work/3df08680c6f85295/mcs/class/corlib/System.Reflection/MonoMethod.cs:232)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at /Applications/buildAgent/work/3df08680c6f85295/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
UnityEditor.HostView.Invoke (System.String methodName, System.Object obj)
UnityEditor.HostView.Invoke (System.String methodName)
UnityEditor.HostView.RegisterSelectedPane ()
UnityEditor.HostView.OnEnable ()
UnityEditor.DockArea.OnEnable ()