Warped rotors "normal"?

Originally Posted by smashwebs

So a while ago I bought a set of Stoptech slotted front rotors for the sport package. I did two track days on them and they were fantastic. Today, I was at the track and while bedding in a set of new pads (before I even had a chance to go out on the track!!) it starts shuddering like a ************. I thought I warped them and swapped them back to the stock ones...which I thankfully had with me. I loved these rotors and the price was great, but should I seek a replacement set or is this common? If this is something common I'm never going to buy them again considering they warped so easily, maybe I had a bad set. So anyways just looking for you guys' experiences and advice.