Either an image file isn't loading or a shader isn't working right. The new rendermanager in CS in conjunction with the move to shaderweaver should resolve alot of rendering issues once its stable (anyone know if cross portal rendering is fixed yet?). PS usually moves along to new stuff in CS as it comes out pretty quickly so in a release or so I'd bet that goes away. Could also be a driver issue or something as said, but I think its more just a combo of some odd bugs that affect more complex CS software.
