But, for the sake of argument, let's assume that driving is not the issue here.
ghoonk, to reduce understeer I'd recommend you fist take a look at playing with your tire pressures - it's probably the easiest thing to do and makes a big difference, plus then you'll be able to rule out the tire variable somewhat.
I recommend looking at your fornt tire wear and, if you're not wearing down near to the outer limits of the tread/shoulder, then try decreasing the front tire pressure slightly until you are whil ekeeping the rear tire pressure consistent. Then at least you can say you're using your front grip properly.
Having 3 degrees of negative camber up front might complicate this approach slightly however it's worth a shot. Since you've already gotten alot of use out of the tires already, no harm in wearing them a little more, eh?