Are image relative paths supported?

Are relative paths supported in the editor?

Here's my problem:

On my dev machine, my web root is:

<root>/dev/project_x/www/

and my absolute path is: "/dev/project_x/www/"

On my production machine, my web root is:

<root>/

so my absolute path is: "/"

Because these paths are different, I cannot get the editor to show images on both servers without changing image paths. The solution is easy: use relative paths... but I cannot figure out how to do this. The weird thing is that relative paths do work in the preview pane of the image properties dialog, but they don't work in the editor. Could this be a bug... is this supposed to work?