If you are on PC, there is a console command that will allow you to remove just level 5 of Sneak. This is apparently triggering the chameleon / stealth boy perma-invisibility glitch on PC. The first is that level 5 of the Sneak Perk is being changed to include a brief chameleon effect.
Bethesda has apparently made 2 changes with the 1.6 Patch that were not good.