After I add image from library I can't publish post or even save draft. After I click button to save post I've got error from my 404.php. It's start when I've upgrade WP to 3.0.
The same problem is when I'm adding image to library, but after error (the same- 404.php), when I back to library I see image is correctly added.
Have you tried:
- deactivating all plugins to see if this resolves the problem? If this works, re-activate the plugins one by one until you find the problematic plugin(s).
- switching to the default theme to rule out any theme-specific problems?
- resetting the plugins folder by FTP or phpMyAdmin? Sometimes, an apparently inactive plugin can still cause problems.
- re-uploading the wp-admin and wp-includes folders from a fresh download of WordPress?
- increasing the available memory?
http://wordpress.org/extend/plugins/memory-bump/
http://wordpress.org/support/topic/253495#post-1017842
Problem solved: Delete image from library, rename, upload. Everything works OK.