I had the same behavior as the people in the follwing posts: https://devtalk.nvidia.com/default/topic/690704/linux/-334-16-parts-of-the-ui-randomly-flicker-when-moving-the-mouse/post/4128101/ https://bbs.archlinux.org/viewtopic.php?pid=1388729 It turns out that it is a bug in media-libs/clutter that was fixed two weeks ago: https://git.gnome.org/browse/clutter/diff/?h=clutter-1.16&id=6665f47d66a871b6e1a5f4200282f42da043a0e8 I've manually allied the patch to clutter 1.16.4 and it fixed all problems I had. You should probably put this patch to portage until clutter 1.16.5 is released.
Confirm! Issue also showed up on my machines and is fixed by applying the mentioned patch.
+*clutter-1.16.4-r1 (08 Mar 2014) + + 08 Mar 2014; Pacho Ramos <pacho@gentoo.org> +clutter-1.16.4-r1.ebuild, + +files/clutter-1.16.4-buffer-age.patch, -clutter-1.16.2.ebuild: + Avoid screen flickering with nvidia drivers (#503560 by brutester), drop old. +
