In my opinion, most front end wandering is due to poor setup or driving technique. Matt

Generalizations can get a guy in lots of trouble. The faster a car goes, the worse any particular problem becomes. Based on the fact that as a group we tend to go faster as time goes by, we WILL find problems getting worse.
Mixing types of tires is not recommended for a reason, and band aiding the problem with more pressure, wider rims etc is just hiding the problem, and looking for trouble.
Case in point, drag slicks of radial construction are so prone to sway at speed Goodyear is coming out with a new radial drag slick with a sidewall construction just to address this issue. The tech guy at Comp Tires west said it will be out in January, roughly. I first had issues back in 2004. M/T radial slicks, 14.5 33 15. Car would swing back and forth so bad I was aborting half the runs I made.
I know some will say this is about FRONT radials vs Back bias, but the fact remains, they drive differently and allow the car to move left or right differently based on tire construction. My scenario just amplified the problem into the extreme. I will not mix tires like this again, been to close to putting the car on its' roof more than once.