When trying to write a post in the visual editor, after publishing it only some of text is actually saved and the rest is lost. The only way I have found to publish is to write it in the html tab and then publish that. After it has been saved, I can go back and edit it in the visual tab to include links, etc.
I use FF 2.0.0.14. The problem has happened for other posters to my blog as well.
I previously had used a plugin called instantupgrade to upgrade from 2.5.0 to 2.5.1 and thought it might have been to blame so I manually downloaded the latest tar to my server and copied over the wp-content dir and my wp-config file.
I deactivated all my plugins to confirm there was no conflict from them. Still having the issue. The content isn't just what was saved from before the auto-save (I wrote 2 paragraphs, and after the auto-save added more text to the first before publishing, that extra bit added to the 1st after the auto-save was there but the end of my 2nd paragraph, written before the auto-save was missing).
Possibly related is that the first auto save takes forever (aka >20 seconds to finally save). Let me know if more information is required, this is a huge problem for me and would love to find a solution ASAP.