The editor always uses root relative paths.
This is because often times you may display the same content on multiple pages that might be in different directories... even in our solutions we have people edit content in /admin/page and then the page is likely in the root. If we used the page relative link as you suggest it wouldn't display in the admin properly.
There is a portability issue when moving between servers that use different root directories, but that can be easily updated with a simple SQL statement to update all of the paths at once.
Did this help? Tips are appreciated...
