Visitors don’t know if they posted

I really need help. I know it’s a holiday week-end, so, perhaps, now, more folks who know WordPress are here to help.

I moved my site to the root directory after successfully upgrading to WordPress 2.8 Followed Codex for doing that. And did the automatic install to 2.8 Now I have some problems.

1) whenever I attempt a preview of a draft post – I am returned with a message that says I do not have permissions to see the draft.

and 2) I’m having problem with folks posting comments – they don’t know if they have posted. The post, they say, has just disappeared. Many leave two posts. And, I fear, some folks just go away.

I’m on a MAC O x.5.7 Using Safari (but also Firefox and Opera) and my blog address is: https://www.bfmcmillen.com

I have made changes to .htaccess, changed read/write, and reinstalled the 2.8 update.

I need some help from someone who understands. This is actually making a difference for my blog which is not positive. I am new to this.

Thanks so much.