Hey man!
when the approach hold is on and the autopilot is activated you shouldn't touch any thing.... it does it alone.....
besides.... rudder cannot be activated at once, especialy not on decends when your speed is greater than the power the engine ativates... because when you apply the rudder you do change the engines' power direction but it's still much weaker than the orantation power of the plane (I am not sure about the spelling, but it's that law in physics that says that every item with a mass will always want to keep his current motion...in this case- forward)

so, when you rudder, especially at decends give it some time before you expect the effects....

Liran Bar, Israel