I'm a new user, having the same sort of problems, on a mac, with firefox.
It's making me feel like an idiot. I just want nicely formatted posts, and all I get is garbage. Turning off the visual editor helps only a little bit.
Can anyone direct me to a site that explains how to format posts in WordPress? It seems the simplest html code is impossible and ignored.
I'm so frustrated I feel I should just go back to creating web pages from scratch in a text editor, and give up on using a blog at all.
I'm not trying to do anything fancy. Inserting line breaks would be great. I don't get how everyone else does this, and why it's supposed to be such a great simple and fast way to post articles to the web.
I can't seem to find any tutorials or help for this. I suppose for every one else it just works.