Tempurpedic owners: do your fitted sheets slip?
I own a Tempurpedic Celebritybed, which is the one with the extra pillow-top on it, and I have noticed that no matter how deep of a fitted sheet I put on it, the sheet comes off one corner every night. No matter what I do, the sheet comes undone, but only on that one corner, and only in one direction. I heard it has something to do with the cashmere top and the direction of the fabric, but how do I stop this from happening? It makes it a pain in the butt to make the bed every morning.

You are correct it does have something to do with the cashmere fabric. You need to get those elastic things with clips on both ends, you should be able to get those at a fabric store. That should solve your problem.