img src tags include server name

Post stripped the page source example. Here it is:

<div class="acidfree-item acidfree-image"><a href="/art/galleries/student-galleries/jamie-arnold-triptic?size=_original" class="active"><img src="http://cerberus.fa.umt.edu/art/system/files/images/albums/PK452_Triptic.preview.jpg" alt="Jamie Arnold Triptic" title="Jamie Arnold Triptic"  class="image image-preview " width="640" height="427" /></a></div><

Okay, so the initial post has been butchered:

I am using Drupal 6, Image, Acidfree Albums, URL rewrite, and Clean URLs. Regardless, using just Drupal base with Image enabled, when viewing image nodes, the tag includes the server name. I'm not sure this should ever be the case, but in the least, it should be configurable. For example:

<div class="acidfree-item acidfree-image"><a href="/art/galleries/student-galleries/jamie-arnold-triptic?size=_original" class="active"><img src="http://cerberus.fa.umt.edu/art/system/files/images/albums/PK452_Triptic.preview.jpg" alt="Jamie Arnold Triptic" title="Jamie Arnold Triptic"  class="image image-preview " width="640" height="427" /></a></div>

The server 'cerberus.fa.umt.edu' is not accessible via the web, as this server is behind a reverse proxy. I have configured settings.php properly to use this reverse proxy, but no matter the local server name keeps getting injected. I can change settings.php and give a base_url = 'http://server/art'; and get it to work from that context, but I also want the site locally accessible on the internal side of the reverse proxy without having to rewrite every link throughout the site or constantly change the server name in base_url. There is no good reason to inject the server name since this is a local, relative link.

Any suggestions?