I have just spend some VERY frustrating days fighting with Blogspot/Bloggers online editing, as I was finishing my "Guide to OpenJDK" article. Avoid using the "a name" tag at all cost, it is normally used to create internal links to chapters in a webpage. When you switch to the preview or compose page, Blogger scripts automatically duplicate this tag EVERYWHERE throughout the text for some bloody reason. Before header tags, inside header tags, after header tags, before links, before images, before every paragraph, before lists, inside every list item.... You will have to spend hours removing them... and if you miss one, like I did, it will metatasize like a cancer all over your text if you switch editing mode again! Fun!!
Also it doesn't save your original hand edited HTML. If you use the "lesser than"/"greater than" html elements to show, for instance, an email address, when you go to compose window everything looks ok, but when you switch back to editing html it will try to parse what is inside the "tag" characters, fail and delete your text.