Your if statement wants the user to be able to posts AND pages, which only applies to admins and editors by default. Are you sure editors cannot see the buttons? If you want anybody who can edit posts to see the buttons (e.g. authors and contributors) take out the check for edit_pages or make it an or statement (which is an unlikely situation in most installs, but I suppose it could happen).
So, instead of:
if ( current_user_can('edit_posts') && current_user_can('edit_pages') )
Use
if ( current_user_can('edit_posts') )
or
if ( current_user_can('edit_posts') || current_user_can('edit_pages') )