I noticed some of my comments disappearing without me triggering this (at least not that I am aware of). Example: placed a comment in reaction to this question. It's now gone.
Anyone an idea what is happening?
Comments are meant to be temporary: to solicit clarification or point out potential edits, that sort of thing. So they tend to get deleted. If a comment doesn't really add anything substantial, it's liable to be deleted more quickly.
So basically, if your comments disappear, don't worry, that's just the system working as intended. If you have something to say that is worth preserving, something that you don't want to disappear after a while, put it in an answer. (Obviously, it should be something that actually does constitute an answer to the question.)