I just experienced this bug on a return mission from the Mun. I had read something about it earlier so I was very careful to keep my reentry very shallow. I did 3 aerobraking passes at 50,000 feet starting the final descent at about 2200 m/s, at first all was well, my ablator was going down, I had SAS on, and at around 26000 meters the oscilations started. I did all I could to keep the craft from flipping, but in the end, it flipped at around 24000 meters. The only thing I could think to do was to pull my chutes, and strangely enough, despite the cloud of superheated plasma surrounding my craft, the chutes deployed, flipped me around and saved the 1+ hour flight from disaster. I had a quick save, so after exiting and backing up my persistent save, I went back and tried several more times, no matter what I did, this happened. I tried controlling it manually, not controlling manually, sas, no sas, no matter what it flipped and exploded, unless I pulled the chutes. This doesn't exactly seem like a fix, but it does seem to help. Hopefully Squad will fix this quickly, it is a pretty game breaking bug. In the mean time, I will try the physics fixes listed above.