Here's something I recently read about warped brake discs that might also interest some of you.
Incidentally, this issue doesn't just affect the original KTM-Galfer discs; while it does occur disproportionately often with them (maybe because of particularly cheap quality), the problem crops up occasionally with the stock discs from other bike manufacturers as well.
What I read was that bikes that are frequently ridden in city traffic are particularly affected; and the connection might lie in the fact that they more often stop at traffic lights with hot discs while keeping the brake applied. This means the pads remain clamped tightly against the hot discs, potentially causing them to warp because they cannot cool evenly and the tension cannot distribute uniformly due to the clamping force of the pads.
I’ve no idea, if that’s the actual cause (and brake discs should certainly be designed so that this isn't an issue!), but from a technical standpoint, it certainly sounds plausible.
As for my 801; I had absolutely no issues with the stock discs; and I hardly ever ride in the city; but maybe that’s just a coincidence...