[UT2004] Mutator Modifying Adrenaline

[SlayerDragon]

I am trying to randomly set the amount of points a pill gives you to a negative amount. Here is the code:

var() float chanceOfDowner;

function bool CheckReplacement(Actor Other, out byte bSuperRelevant)
{
	local AdrenalinePickup P;
	if( AdrenalinePickup(Other)!=NONE )
	{
		if( FRand() <= chanceOfDowner )
		P = AdrenalinePickup(Other);
		P.AdrenalineAmount = - P.AdrenalineAmount; //invert adrenaline amount
	}
	return false;	//don't replace
}

defaultproperties
{
	chanceOfDowner = 0.5;
}

This refuses to change the AdrenalineAmount! I have tried doing it like this:

	P.default.AdrenalineAmount = - P.default.AdrenalineAmount;

Still, no effect. I tried changing the pickup message, and this is the only one that worked:

	P.default.PickupMessage = "Downer ";

However, this changes the pickup message for ALL pills in the level.

Anyone know what I am doing wrong?