Hi,
this is my sound init and no problems with a6.6com and a7.06com.

Code:

---

	...
	cam_ansicht = 1;			// Fahrzeug Aussenansicht

	eng_vol = 100;			// Aktuelle Lautstaerke (Motor_Sound)

	if(enghandle1 == 0)
	{
		enghandle1 = ent_playloop(my, motsnd_string_ptr[veh_daten[14]], eng_vol);
	}
	else
	{
		snd_tune (enghandle1, eng_vol, eng_pitch, null);
	}

	rpm_pitch[0] = veh_daten[18];
	rpm_pitch[1] = veh_daten[19];
	...

---

have you a debugpanel to show the pitch var ?
write a test function and play with the pitch var, control the pitch var with keys.