Just a thought. I use Norton firewall.
I had many of the problems you described when my firewall was on. When I turned it off the pages loaded normally, but I had to go to a different page and then go to the saved listing page. If I just reloaded the page it wouldn't work.
Also if your pop up blocker is on it does some strange things. As in when you browse for catagories it saves the auction about 50% of the time.