Is anyone else having problems with
the rotors warping on a 99 Tahoe 4x4?

Yep, pretty common with most SUV's.. Time for new rotors/pads. My Powerslots w/Hawk HPS pads work nicely...

I also have a 99 Tahoe and warped some rotors after approximately 15k miles. Heavy vehicle - lots of heat. Based on my experience and those on other BB's, you may want to consider the following after you install new rotors.

Cross-tighten lug nuts increasing the torque each time e.g. 40lbs, 70lbs, 100lbs, 125lbs. Don't let anyone use a pneumatic wrench on your lugs even if they have the color-coded torque shafts!!!

Make sure that your back brakes are properly adjusted so all of the braking work does not default to your front brakes. Although the brakes are suppose to be self-adjusting, many have knocked out (or drilled) the access plugs in the backing plates, and now adjust manually every 3k to 5k miles. Made a big difference for me.

Good luck

Thanks for the info -
Didn't realize when I bought it
that would be an issue - oh well,
live & learn I guess

Mine are warped as well but I'm living with it. It doesn't cause too uch trouble unless I have to really mash my brakes hard. I'm waiting until I really have to replace them. It stops as it should.