diff -r ea9bf60acd97 css.visual/src/org/netbeans/modules/css/visual/ui/preview/CssPreviewPanel.java
--- a/css.visual/src/org/netbeans/modules/css/visual/ui/preview/CssPreviewPanel.java	Fri Mar 26 06:52:24 2010 +0300
+++ b/css.visual/src/org/netbeans/modules/css/visual/ui/preview/CssPreviewPanel.java	Fri Mar 26 10:07:37 2010 +0100
@@ -41,7 +41,9 @@
 package org.netbeans.modules.css.visual.ui.preview;
 
 import java.awt.Graphics;
+import java.io.File;
 import java.io.InputStream;
+import java.net.URL;
 import java.util.concurrent.FutureTask;
 import java.util.logging.Handler;
 import java.util.logging.Level;
@@ -49,10 +51,18 @@
 import java.util.logging.Logger;
 import javax.swing.JComponent;
 import javax.swing.SwingUtilities;
+import org.netbeans.api.project.FileOwnerQuery;
+import org.netbeans.api.project.Project;
+import org.netbeans.modules.web.common.spi.ProjectWebRootQuery;
 import org.openide.awt.StatusDisplayer;
+import org.openide.filesystems.FileObject;
+import org.openide.filesystems.FileStateInvalidException;
+import org.openide.filesystems.FileUtil;
 import org.openide.util.Exceptions;
 import org.openide.util.RequestProcessor;
+import org.xhtmlrenderer.extend.UserAgentCallback;
 import org.xhtmlrenderer.simple.XHTMLPanel;
+import org.xhtmlrenderer.swing.NaiveUserAgent;
 
 /**
  * JPanel wrapping XHTMLPanel, the Flying Saucer's rendering area.
@@ -80,7 +90,7 @@
             @Override
             public void run() {
                 //create outside of AWT
-                final XHTMLPanel panel = new PatchedXHTMLPanel();
+                final XHTMLPanel panel = new PatchedXHTMLPanel(new PreviewUserAgent());
                 //and set the panel to this component in AWT
                 SwingUtilities.invokeLater(new Runnable() {
                     @Override
@@ -196,6 +206,16 @@
 
     //workaround for FlyingSaucer bug (reported as netbeans issue #117499 (NullPointerException for unreachable url))
     private static class PatchedXHTMLPanel extends XHTMLPanel {
+        /**
+         * Instantiates a panel with a custom {@link org.xhtmlrenderer.extend.UserAgentCallback}
+         * implementation.
+         *
+         * @param uac The custom UserAgentCallback implementation.
+         */
+        public PatchedXHTMLPanel(UserAgentCallback uac) {
+            super(uac);
+        }
+
         @Override
         public void paintComponent(Graphics g) {
             try {
@@ -208,5 +228,33 @@
             }
         }
     }
-    
+
+    //workaround for specifying Base URL
+    private static class PreviewUserAgent extends NaiveUserAgent {
+        @Override
+        public String resolveURI(String uri) {
+            if (uri == null) {
+                return null;
+            }
+            if (uri.startsWith("/")) {
+                // Absolute path now we will look to the webRoot of the project
+                FileObject edited = FileUtil.toFileObject(FileUtil.normalizeFile(new File(getBaseURL())));
+                if (edited != null) {
+                    FileObject webRoot = ProjectWebRootQuery.getWebRoot(edited);
+                    if(webRoot == null) {
+                        //no web root, use project's root
+                        Project project = FileOwnerQuery.getOwner(edited);
+                        webRoot = project.getProjectDirectory();
+                    }
+                    try {
+                        return webRoot.getFileObject(uri).getURL().toExternalForm();
+                    } catch (FileStateInvalidException ex) {
+                        // ignore it and falling back to flysaucer implementation
+                    }
+                }
+            }
+            // falling back to FlyingSaucer implementation
+            return super.resolveURI(uri);
+        }
+    }
 }