I usually delete files (folders too) with shift-delete rather than delete; you know, so it says "are you sure you want to permanently delete" rather than "are you sure you want to ... recycle bin" (and with a different icon).
From time to time, the icons on my desktop rearrange, all to the left. I do not have auto arrange icons set. I have Ez-desk, so it's not a major problem to put them back where I want them, but it _is_ irritating.