Flash: The file 'MemoryStream' is corrupted! when Instantiate CharacterMotor

Hi, I'm having a problem with the flash export in Unity 3.5

When running the game in the flash content debugger and I try and Instantiate a prefab containing a CharacterMotor component I get this message.

The file 'MemoryStream' is corrupted! Remove it and launch unity again!
[Position out of bounds!]
LogCallStackError
    at com.unity::UnityNative$/Ext_Flash_LogCallstack()
    at com.unity::UnityNative$/_Z17DebugStringToFilePKciS0_iiii()
    at com.unity::UnityNative$/_ZN12CachedReader16OutOfBoundsErrorEjj()
    at com.unity::UnityNative$/_ZN12CachedReader4ReadEPvj()
    at com.unity::UnityNative$/_ZN18StreamedBinaryReadILb0EE21TransferSTLStyleArrayI13dynamic_arrayI11KeyframeTplIfEEEEvRT_17TransferMetaFlags()
    at com.unity::UnityNative$/ReadAnimationCurveAndReturnPtr()
    at UnityEngine.Serialization::SerializedStateReader/ReadAnimationCurve()
    at global::CharacterMotorMovement/Deserialize()[C:\Users\Gick\Development\Unity Projects\FlashTest\Temp\StagingArea\Data\ConvertedDotNetCode\global\CharacterMotorMovement.as:66]
    at UnityEngine.Serialization::SerializedStateReader/ReadIDeserializable()
    at global::CharacterMotor/Deserialize()[C:\Users\Gick\Development\Unity Projects\FlashTest\Temp\StagingArea\Data\ConvertedDotNetCode\global\CharacterMotor.as:369]
    at UnityEngine.Serialization::ActionScriptDeserializer$/Deserialize()
    at com.unity::UnityNative$/Ext_DeserializeMonoBehaviour()
    at com.unity::UnityNative$/_ZN13MonoBehaviour23VirtualRedirectTransferER18StreamedBinaryReadILb0EE()
    at com.unity::UnityNative$/_ZL15CloneObjectImplP6ObjectR10vector_mapIllSt4lessIlE13stl_allocatorISt4pairIllEL18MemLabelIdentifier93ELi4EEE()
    at com.unity::UnityNative$/Object_CUSTOM_Internal_CloneSingle()
    at UnityEngine::_Object$/Object_Internal_CloneSingle_Object()
    at UnityEngine::_Object$/Object_Instantiate_Object()
    at global::Spawner/Spawner_Update()[C:\Users\Gick\Development\Unity Projects\FlashTest\Temp\StagingArea\Data\ConvertedDotNetCode\global\Spawner.as:22]
    at com.unity::UnityNative$/Ext_Flash_InvokeMethodOnObject()
    at com.unity::UnityNative$/_ZN13MonoBehaviour16CallUpdateMethodEi()
    at com.unity::UnityNative$/_ZN13MonoBehaviour6UpdateEv()
    at com.unity::UnityNative$/_ZN20BaseBehaviourManager12CommonUpdateI16BehaviourManagerEEvv()
    at com.unity::UnityNative$/_ZN16BehaviourManager6UpdateEv()
    at com.unity::UnityNative$/_Z10PlayerLoopbb()
    at com.unity::UnityNative$/NativeExt_PlayerLoop()
    at com.unity::UnityContentInternal/playerLoop()
    at com.unity::UnityContent/onEnterFrame()

I'm planning on getting round it for now by creating all of the required CharacterMotor containing objects in the editor and then enabling them at run time but I would like a better solution.

Thanks in advance.

n.b. I've tried this in both c# and js, using the flash content debugger 11.2.

I've also created an example project (download here) showing the problem, you will need to build a swf and then run it in the content debugger...