Mounir Fireman

Update: It actually was because of mip-mapping, but only when I had mip mapping turned off, it would stop flickering.

no it wasn't related to Mip-Mapping, as it was at the highest setting of mip mapping. Also, I restarted minecraft and it suddenly didn't do the white flashes anymore.

I have the same problem too, I first noticed it right after updating, while mining in the Nether. Afterwards, when going on an adventure I noticed that no hostile mob spawned which didn't really make it an adventure,