With Unity 3.5.6f4, after importing the PlayMaker package, when I compile in MonoDevelop it reports the following errors for the Assembly-CSharp-Editor project
123 No overload for method 'HelpButton' takes '0' arguments (CS1501) in FsmComponentInspector.cs
163 No overload for method 'DoValueGUI' takes '1' arguments (CS1501) in FsmComponentInspector.cs
The Unity editor does not report these errors, nor does compiling in VS 2010