If you add entires regularly, they are ordered by date, last entries on top. This is normal and perfectly acceptable. But if you discover an error in an old entry and edit it, upon saving it goes to the top, as if it were the last added one.

In short: entries are ordered according to its modification date instead of its creation date, which leads to a lot of trouble if your entries are logically sequential as, for example, in a sequence of lecture's summaries (which is my case).