I've had Kenda Kwests(26x1.5",65psi) on three bikes so far with no issues. But recently I've seen a couple problems pop up at my bike clinic.
The first was a man who brought his bike back after I had gone over it and inflated the tires to the proper level. The rear tire had come off the rim. I was sure I hadn't overinflated it,and when I checked the tube it was fine(had not burst). The tire went back on very easily,but I didn't think anything of it. He insisted he hadn't hit a pothole or jumped a curb,so I put everything back together and reinflated it to a little under max and he rode it away with everything seeming normal. The next was a lady whose tires were both flat. She said that months earlier she had just been walking her bike and the front tire just popped off(she had taken it to a shop to get it fixed). Both tires had crooked valve stems,so I decided to remove the tires and ensure the tubes weren't kinked. The tires were so 'loose' on the rims,that I was able to put three fingers between the tire and rim with the tire still on the bead. In fact,I was able to remove the schrader valve from the rim by just lifting the tire off the bead. I advised her that her tires should fit better than that and she agreed to not ride the bike until she purchased replacements. In both cases the tires were 700x38,85psi Kwests.
I asked about this on a local blog,and was told by a friend who works in a shop that he has seen this problem with these tires several times. Can anyone here confirm that they've seen Kwests come off the rims? Both bikes at my clinic were lower-end models,so I could maybe see a cheap wheel not holding the bead on a high pressure tire,but these were only 85psi,and no way you should be able to see through a gap between the tire and rim when the tire is on the bead.