[Noob] Operator overloading - am I missing something?

[Anders Runesson]

Hi there. 
I'm converting some old C code to D, but I'm stumbling on this:

...

alias GLdouble Scalar;

...

class Vector {
	private Scalar[4] data;

	...

	Vector opMult(Scalar s) {
	
	...			
	
	}
	
	Vector opDiv(Scalar s) {
		
		return this * (1.0 / s); // Doesn't work
		
		//return this.opMult(1.0 / s); Works as I expected
	}

	...

}

I am trying to overload the division operator, but I can't use the
multiplication operator I just overloaded(or at least thought I did).
The compiler says 

vector.d(112): incompatible types for ((this) * (1 / cast(double)(s))): \
'bagle.math.vector.Vector' and 'double'

vector.d(112): 'this' is not an arithmetic type

and refuses to compile the code. The commented out line works fine.
Why is this? I thought this.opMult(s) and this * s were synonymous?

I suppose I'm missing something, but from just reading the spec I couldn't
figure it out.

Thanks
/Anders