Unmanaged C++ template in managed C++ throws bad image?

I have a Managed C++ dll which dynamically links with an unmanaged C++ dll. The managed C++ derives several unmanaged classes from abstract interfaces in the unmanaged dll.

This works fine. ICustomer.h in unmanaged dll

//  uses macro __declspec(dllexport)
class EXPORT_API ICustomer
{
public:
    virtual void PlaceOrder() = 0;
    //...
};  

LocalCustomer.h in managed C++

#include "unmanagedlib/ICustomer.h"

//an unmanaged derived class defined in the managed dll
class LocalCustomer : public ICustomer
{
public:
    void PlaceOrder();
    //...
};  

LocalCustomer is used in the Managed dll. I can pass it to functions in the unmanaged dll and it all works fine.

Here is the problem. I get an STATUS_INVALID_IMAGE_FORMAT at startup when I try to implement an interface which exposes a template.

Does not run. in unmanaged Dll

stuct Order
{
    double price;
    //...
};

template<typename T>
class EXPORT_API ICollection<T>
{
    //...
};

class EXPORT_API IFactory
{  
public:
    virtual ICollection<Order>& GetOrders() = 0;
}

in the managed C++ dll

class OrderCollection : public ICollection<Order>
{
    //...
};

class LocalFactory : public IFactory
{
public:
    virtual ICollection<Order>& GetOrders() { return m_orders; }
private:
    OrderCollection m_orders;
};

I have narrowed it down the template override GetOrders. Having the code in the managed dll causes a dialog to open "The application was unable to start correctly (0xc000007b) which is just the STATUS_INVALID_IMAGE_FORMAT HRESULT getting thrown by the managed loader. Removing the code allows it to run. So whats wrong with the template? Why can't I use it in the managed dll.

One other clue, not sure if this is a distraction of not.. I am compiling a 32 bit app and running on Win7 x64. Like I said with works just fine as long as the template does not cross the dll from unmanaged to managed.

What kills me is I I have several unmanaged C++ templates that live wholly within the managed dll and they work fine. It is just templates crossing between the dll that seems to give me bad image.

I am not sure, but it seem to me you can't export generic (template) classes from a dll. Templates get instantiated when referenced in code at build time. This means that template's source code has to be visible at build time, which is not the case. You have a precompiled dll, how would you expect template instantiation?