I find that when composing a post, preview is not working for me.
By this I mean formatting is lost. So I can't see italics etc, links, or paragraph breaks.
It's all written in one block of text, with tags. I can only see final format when I post, which shows correctly.
I don't have this in other forums.
Have I got some setting wrong? Should I be using a particular browser?
You're not doing anything wrong (unless we're both doing the same thing wrong) - the 'preview' function doesn't show you a meaningful preview, instead removing all formatting.
If you're familiar with BBCode formatting, you can use this to format your posts. Alternatively, make sure the the 'View Source' button in the top right is unchecked, and you'll see a decent approximation of the formatting that will be applied to your post:
