A bug in 2.1.6 using infinite lightsources when in modeling mode and preview-mode ("smooth shading"):
Some sort of weird black&white stipling appears on vertical surfaces (no matter how subdivided that surface is) when using an infinite lightsource in a vertical only position. This bug is not present in 2.1.5. Some surfaces also appear to have inversed shadowing.
PS: I had to dig up an old e-mail from 2013 to be able to login, since my request for a new one did not work; I never recieved a new password to my e-mail address S