There's corruption somewhere. Somewhere, either in RAM, VRAM, or on your disk drive, data is being incorrectly read/stored. That the error is recurring leads me to believe you have a hardware issue, not software. I recommend S.M.A.R.T tests on your drive (http://hddscan.com/), pre-boot memtests (http://memtest.org/), and maybe some VRAM tests (http://mikelab.kiev.ua/index_en.php?...ROGRAMS/vmt_en).