wrong datatypes generated by dumpccp

I am using dumpcpp to generate the interface of an ActiveX element driving an ultrasound system.

One of the function generated by dumpcpp is

inline bool TTRFReceiver::GetZoneInfo(int zone, int& pStartSample, int& pEndSample, double& pMetersPerSample, double& pTransmitFrequency, double& pFocusDepthCM)
{
bool qax_result;
void *_a[] =

{(void*)&qax_result, (void*)&zone, (void*)&pStartSample, (void*)&pEndSample, (void*)&pMetersPerSample, (void*)&pTransmitFrequency, (void*)&pFocusDepthCM}

;
qt_metacall(QMetaObject::InvokeMetaMethod, 45, _a);
return qax_result;
}

When I use this function with the suggested dada types I get the error

QAxBase: Error calling IDispatch member GetZoneInfo: Type mismatch in parameter 1

although I definitely use an int as first parameter.

Using other tools to generate the interface results in the parameters
GetZoneInfo(short, short&, short&, double& double&, double&) (short's instead of int's)

This interface works well and is also documented by the vendor of the ActiveX element.

This seems to be a bug of dumpcpp.

Furthermore, dumpcpp ignores the namespace option -n as well as the option -compat. Using these options does not change anything.