ERROR 403 Forbiden apearing

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.

thanks for your reply.
i tried deactivating all plugins and switching to default theme – both of these did not work.

i have a suspicious this problem is either related to the permission settings (i was using cyberduck and have since read that it can cause problems) but i have tried changing the permissions to 777 and still this does not work. As well, the problem only exists for certain posts. Some of them are still editable. AND I was also having similar problems with certain images that I would upload to the directory where it said they were forbidden but the permissions seemed fine.

Another reason I suspect this might be a problem is that I recently changed the “nickname” to use when posting – could this be part of the problem? I changed it back to the original nickname of “admin” but still no luck.

any more advice?
thanks!