I haven't had issues with my screensaver, I have used both Dreamy and the built in one. Have you tested switching back to the default screensaver and seeing if the problem is resolved? That would be the first thing to do if you haven't. If it still is an issue with the default, then maybe search for the issue on the nvidia forums then make a post there if you can't find anything on it. I'm sure you will get a better connection to the devs that push updates and fix bugs there.