Unity 4.0 Flash Export load->unload->load crash

In Unity 3.5 Flash Export I could load the swf, unload and reload it without it crashing... now that i upgraded to 4.0 I'm getting this problem.

On first init everything loads fine and there are no problems. It hits shutdown and I do:

 mUnityLoader.unityContent.setContentHost(null);
 removeChild(mUnityLoader);
 mUnityLoader.unload();
             mUnityLoader.contentLoaderInfo.removeEventListener(Event.COMPLETE, onUnityContentLoaderComplete);
             mUnityLoader.contentLoaderInfo.removeEventListener(ProgressEvent.PROGRESS, onUnityContentLoaderProgress);
 mUnityLoader = null;

Then when I hit the init again I do:

 var params:UnityLoaderParams = new UnityLoaderParams(false, width, height, false);
             mUnityLoader = new UnityContentLoader(UnityFileUtility.getSWFPath() + swfName, this, params, false);
             mUnityLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onUnityContentLoaderComplete, false, 0, true);
             mUnityLoader.contentLoaderInfo.addEventListener(ProgressEvent.PROGRESS, onUnityContentLoaderProgress, false, 0, true);
             mUnityLoader.loadUnity();

On this second pass it breaks before the load completes and I get this:

TypeError: Error #1034: Type Coercion failed: cannot convert System::ClassType@19da38c9 to System.Type. at System::Type$/ForClass() at System::CLIByteArray/CLIByteArray_Constructor_Vector$1_ByteArray() at System::CLIArrayFactory$/NewByteArrayWithLength() at System.Text::ASCIIEncoding/Encoding_GetBytes_String() at UnityEngine::WWWTranscoder$cinit() at global$init() at UnityEngineClassIndex$/InitializeClasses() at com.unity::UnityNative$/init_actionscript_cctors() at com.unity::UnityNative$/Native_Init() at com.unity::UnityContentInternal/initNativeEnvironment() at com.unity::UnityContent/onFrameInitStep()