Chain skipping despite new cassette and chain My chain keeps skipping loudly. Replacing the cassette and chain had no effect. I also zeroed the derailleur to the 5th gear of the cassette and it shifts smoothly. I have also replaced all ball-bearings and assorted fittings at suspension joints. The freehub seems to work properly. I feel it may be due to frame flex, since I ride a full suspension MTB (poison bikes) and it has noticeable frame flex when pedaling. Undesired gearshifting happens when I turn. I have replaced aluminum washers at the main suspension joint near the bottom bracket several times and this solves the problem for about three months. Has anyone experienced this and have another idea how this can be fixed permanently? 

Details: 27 gear MTB, full suspension

UPDATE: Jan 9th: I replaced a washer in the Suspension tightening it up a bit and reducing Frame Flex but the problem persists albeit slightly improved. Based on Responses here I have been watching the chain and noticed that it sometimes bunches up when coasting (not pedalling) -- it seems that the cassette keeps moving despite the pedals being stationary.
I had a similar problem with my road bike.  I replaced the cassette and it still skipped.  I replaced the chain and it still skipped.  Finally, I changed the rings and it worked perfectly. The rings looked only slightly worn but I think one or two of the teeth were shortened slightly through excess use.  I saved the rings just for a side-by-side comparison with future rings.