I have installed the newest version of WordPress but started having different kinds of problem related to ajax.
First my tinymce editor refused to load. This is not a big problem cause I prefer fckeditor.
Bigger problems are with deleting posts/pages, inserting custom fields and uploading images.
When I try to delete a post WordPress asks me wether I'm sure, when I choose yes the post flashes red and disappears but returns back to the listing after a short moment. The background of the post is now red. Also a small notice box appears in the bottom of the post listing, but there is no text in the box - only the number 1. When I load the page again the deleted post has disappeared.
Another problem is with inserting custom fields. When I add a custom field it does not appear at the top of the form like it should. When I save the post and return to edit it the custom field has appeared. When I try to update it the same mysterious notice box with the number 1 appears.
Finally when I upload an image to a post the whole upload form disappears. I get it back when I again save the post and open it again. The image has uploaded.
So it seems that I am experiencing different kinds of problems with ajax related functions. I edited the edit-post-rows.php -file and removed the line which enables the "are you sure" -box. This is not a good solution cause it's now easy to accidentally delete a post.
I am using firefox 2 on a mac.