Happens many times lately. Usually when I go to running a program or am ready to reboot my computer. When it happens all my open folders close, my desktop re-arranges itself, and sometimes my desktop disappears and I am left with an empty desktop where I can only reboot.
This does not happen very often, but lately once or twice a day. Overall I have a decent computer but can't figure out why this happens. It is not a big issue, but would be nice to know why it happens.