Some images not diplaying with clean URLs on.

I having some problems with displaying some images (in blocks) on my site while using 'clean URLs'.

The site itself is working well (with clean URLs on or off). All 'top level' pages, including adds, blocks, nodes, taxonomy images, etc work as expected. The problem exists when I try to go to a 'deaper' level.

Example. I have created pages like: http://www.example.com/about with some related images in blocks in the side columns... ( I have set these block to only display on related pages by putting about* in the space provided after selecting the 'display only on listed pages' option in the relevant block configuration page).

The blocks contain code like this: <center><img src="files/about/myphoto.jpg"></center> (image files have been uploaded to the server and permissions checked, etc)

All of this works exactly as it should until I go to a deaper level.

Let's say i create a page (node/56 ... or whatever) and create an alias node/56 >> about/myjob When I surf to http://www.example.com/about/myjob everything works fine (clean URLs work)... except the blocks on the sides of the page: the are empty (in Firefox) or show the little red X (IE) .

Clicking on the 'properties' of the image (IE) shows that the browser is looking in http://www.example.com/about/myjob/files/about/myphoto.jpg and NOT in http://www.example.com/files/about/myphoto.jpg where it should be looking... so it is using a 'relative path' from the current node.

When I turn clean URL's off, everything works perfectly. All 'block' images are displayed where and when they should be.

I've been working on this for hours and have searched google, drupal.org, apache.org... I have also checked and rechecked my apache settings and my .htaccess file etc....

I know I can get around this by using a full URL (FQDN) with each image but this is a development site (developed offline) and will be moving to a new domain when complete. Besides, I prefer to use relative paths where possible.

I'm using Ubuntu 7.10, Apache 2.2, Mysql 5.0.45, drupal 5.7

Any ideas?