Mixed managed\unmanaged dll causing problems with std::vector clear()

[hanthehead]

In order to use a C# dll from our unmanaged C++ project I have created a mixed managed\unmanag ed c++ dll.
This dll is passed an unmanaged class which contains vector<CDBRecor d> m_vecRecords member variable. Within the managed C++ dll m_vecRecords is added to. This all works fine until our unmanaged C++ project attempts to m_vecRecords.cl ear() and I get an exception.

"Microsoft C++ exception: std::bad_alloc at memory location 0x0012ed68.."
and execution stops at
> msvcp90d.dll!st d::allocator<ch ar>::allocate(u nsigned int _Count=23152035 57) Line 151 + 0xb bytes C++

	void destroy(pointer _Ptr)
		{	// destroy object at _Ptr
		_Destroy(_Ptr);
		}

then

	pointer allocate(size_type _Count)
		{	// allocate array of _Count elements
		return (_Allocate(_Count, (pointer)0));
		}

Here are some exerts of my code....I hope you can help!

// IReadDatabase.h
#pragma once
#include "stdafx.h"
#include <vector>

#pragma unmanaged

class StringPair
{
public:
	char *key;	/* optional element of type xsd:string */
	char *value;	/* optional element of type xsd:string */
	StringPair();	/* transient */
};

class CDBRecord
{
public:
	CDBRecord(long dbID = -1);
	
	StringPair *__ptr;
	int __size;
};

class CHitlist
{
public:		
	CHitlist() {}
	
	long				m_hit_total;
	
	std::vector<CDBRecord>   m_vecRecords;	
};
.....

// ManagedDll.h

#pragma once

#include <IReadDatabase.h>

#using <..\..\Shared Libraries\c#DLL.dll>
using namespace System;
using namespace System::Collections::Generic;
using namespace c#DLL;

#pragma managed

namespace ManagedDll
{		
	bool CManagedDll::AddRecord(CHitlist* pHitlist)
	{
		CDBRecord rec;
		bool bRet = GetRecord(&rec);
		
		if (bRet)
			pHitlist->m_vecRecords.push_back(rec);

		return bRet;
	}

....