templates and inheritance

Hello,

I have two cl*****, C_A and template<typename T>C_B which are derived 
"private" from the base cl***** C_A_ resp. template<typename T>C_B_. 

The behaviour is quite different. The users of C_B can access the 
variable var of C_B_, but not the users of C_A. Moreover, in C_A the 
visibility of var is also controlable via the construct "private: / 
public: using C_A_::var;", but this is not the case for C_B.

Can sb. explain the different behaviour. 

I'm using the g++ Version 4.1.3.

class C_A_
	{
	public:
		int var;
		virtual ~C_A_( void ){}
	};

class C_A : private C_A_
	{
	private:
		using C_A_::var;
	public:
		C_A( void ){} 
		virtual ~C_A(void) {}
	};


template<typename T>
class C_B_
	{
	public:
		T var;
		virtual ~C_B_( void ){}
	};

template<typename T>
class C_B : private C_B_<T>
	{
	private:
		using C_B_<T>::var;
	public:
		C_B( void ){} 
		virtual ~C_B(void) {}
	};
	
 
int main(int argc, char* argv[]) 
	{
	C_B<int> 	oB;
	oB.var = 5;// no error from the compiler
		
	C_A		oA;
	oA.var	= 5;// error: »int C_A_::var« is not accessible
	
	return 0;
	}//