Used my RiMac for ten days up to now no glitches or anything other than my own lack of knowledge of how to use it ( new to apple). I used it last night and put it to sleep, everything fine. This morning I switched it on and went immediately to the Finder prefs to untick "all files" from view on the sidebar. I went to open finder, and there were no files at all in documents. Everything had gone. I had an OMG moment, clicked it a few more times then after about 20 seconds everything reappeared in Finder. Later I plugged in a USB memory stick. It didn't show on the desktop or in finder. The files had gone again. I decided best to reboot, which immediately showed the USB stick on the desktop and finder, and the files had reappeared in documents. So, a minor glitch caused by some unknown software thing, or anybody else experienced such a thing? Any idea what might have caused it? Last thing I want is a glitchy computer, that's why I came across to Apple in the first place!