In this question, the OP, who is a newcomer, answered to two questions that have been posted as comments directly under her original question, by commenting jakebeal's answer. This indeed doesn't get the commenters notified of the responses.
I've left a comment to the OP by saying that she had answered under the wrong comment list and that her responses would not have been notified to the other commenters.
My comment was deleted in an hour or so, without giving the OP enough time to read it, moving her comments and avoid this mistake in the future. Moreover, also one of the OP's comments was deleted, while the other was left (it is not clear according to which criterion).
So: shouldn't informative comments be left for a sufficient amount of time to be read by the intended readers, especially when they are newcomers?