Since I upgraded to El Capitan - actually it was a clean install which I then migrated my data and apps from my Yosemite setup - every single day at least once or twice, it reverts back to the regular menu from the dark theme. It's not after it goes to sleep, nor even after a restart but does seem to be after the screensaver is on. It's not every time, as I said, just once or twice a day. I then go back in to System Preferences and re-check the box and it works fine - until it decides to change it back again the next day at some point. Any thoughts on what may be causing this or how to fix it? It happened under 10.11 and now 10.11.1 also. Was fine under Yosemite (still is when I boot that system drive). Currently running on a Mac Pro 5,1 (upgraded from 4,1) six-core Westmere 3.2GHz, 16GB, 240GB SSD (on internal PCIe) primary system drive, with 2x1TB RAID0 data/apps. There are no errors reported in logs, it just changes back to the regular menu. I will add that also on occasion the screensaver stops within a few seconds after starting despite no movement of the mouse or input of any kind. Perhaps something is screwy with the screensaver(s)? I appreciate any insight, thanks in advance!