Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.710
diff -u -p -r1.710 common.inc
--- includes/common.inc	4 Nov 2007 21:24:09 -0000	1.710
+++ includes/common.inc	12 Nov 2007 00:17:14 -0000
@@ -1715,8 +1715,8 @@ function drupal_build_css_cache($types, 
           $path = base_path() . substr($file, 0, strrpos($file, '/')) .'/';
           // Wraps all @import arguments in url().
           $contents = preg_replace('/@import\s+(?!url)[\'"]?(\S*)\b[\'"]?/i', '@import url("\1")', $contents);
-          // Fix all paths within this CSS file, ignoring absolute paths.
-          $data .= preg_replace('/url\(([\'"]?)(?![a-z]+:)/i', 'url(\1'. $path .'\2', $contents);
+          // Fix all paths within this CSS file, ignoring absolute paths and paths relative to hostnames.
+          $data .= preg_replace('/url\s*\(\s*([\'"])?(?!([\'"])?(\/|[a-z]+:))/i', 'url(\1'. $path .'\2', $contents);
         }
       }
     }