Problem Eating UCGO cargo

[icedown]

Ok, I've been working on this one on and off all day and I really don't know what I'm doing wrong.

Here's The function

void StationKeeper::updateCargo(double t) 
{
	//Auto refuel tanks
	double fuelMax;
	double fuelCur;
	PROPELLANT_HANDLE mTank = GetPropellantHandleByIndex(0);
	fuelMax = GetPropellantMaxMass(mTank);
	fuelCur = GetPropellantMass(mTank);
	if((fuelMax - fuelCur) > 1.0) {
		double fuelNeeded = fuelMax - fuelCur;
		if(fuelNeeded > t * SK_FUEL_TRANS){
			fuelNeeded = t * SK_FUEL_TRANS;
		}
		
//		double fuelAte = hUcgo.EatCloserFuelCargo(fuelNeeded);
		double fuelAte = hUcgo.EatCloserCargoByType("fuel", fuelNeeded);
	
		if(fuelAte > 0) {
			SetPropellantMass(mTank, fuelCur + fuelAte);
		}
	}


	//Auto grapple nearby fuel cargo
	if(hUcgo.GetNbrCargoLoaded() < 4) {
		hUcgo.GrappleOneCargoByType("fuel");
	}

}

No matter which line I use, EatCloser always return -1.0. There are 4 full space fuel onboard.

t is a timer that is updated every frame by t += simdt and this is dispatched with t > 1.0 and t is reset to 0.

SK_FUEL_TRANS is 1.0 for 1kg/sec fuel transfer.

The GrappleOneCargo works just fine.

What am I doing wrong?