From what I've seen, encapsulated-aluminum disk bottom pans and straight aluminum pans are simply prone to warping. The aluminum is just too soft and can't take the mechanical stress, and the disk-bottom pans have problems with dissimilar metals. Different metals expand at different rates, and thus will separate over time if heated and cooled repeated.
Now, it's possible to get a disk-bottom pan that won't warp or separate, but the outer jacket of stainless must be quite thick, at least 2 mm. The disk in the bottom also has to be completely covered by the steel -- if you can see a different looking metal peeping out, the pan is a no-starter for you. It'll probably be a heavier, thicker pan, with fairly thick walls as well.
The simplest solution is to use a pan that's cast-iron, all-stainless, or multi-ply AKA clad aluminum/copper. Cast-iron is too thick and rigid to warp, and is a homogeneous material, so it isn't prone to problems from dissimilar metals. All-stainless is stronger and more elastic, and again homogeneous. It has lousy heat conduction though.
Multi-ply pans avoid warping because they're better made and incorporate thicker outer layers of stainless, which hold the pan rigid against warping. I think the process by which the aluminum or copper is contained in the stainless is also more robust.