diff -r cc5360887ca1 core.startup/test/unit/src/org/netbeans/core/startup/layers/CachingPreventsFileTouchesTest.java
--- a/core.startup/test/unit/src/org/netbeans/core/startup/layers/CachingPreventsFileTouchesTest.java	Tue Feb 21 08:50:52 2012 +0100
+++ b/core.startup/test/unit/src/org/netbeans/core/startup/layers/CachingPreventsFileTouchesTest.java	Wed Feb 22 14:15:49 2012 +0100
@@ -44,7 +44,11 @@
 
 package org.netbeans.core.startup.layers;
 
+import java.beans.PropertyVetoException;
+import java.io.File;
 import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.logging.Level;
@@ -55,6 +59,9 @@
 import org.netbeans.junit.NbTestSuite;
 import org.openide.filesystems.FileObject;
 import org.openide.filesystems.FileUtil;
+import org.openide.filesystems.LocalFileSystem;
+import org.openide.modules.InstalledFileLocator;
+import org.openide.modules.Places;
 import org.openide.util.Lookup;
 
 /**
@@ -94,10 +101,12 @@
                 CachingPreventsFileTouchesTest.class
             ).reuseUserDir(true).enableModules("platform\\d*", ".*").enableClasspathModules(false)
             .honorAutoloadEager(true);
-            conf = conf.addTest("testReadAccess").gui(false);
+            conf = conf.addTest("testReadAccess", "testRememberCacheDir").gui(false);
             suite.addTest(conf.suite());
         }
-
+        
+        suite.addTest(new CachingPreventsFileTouchesTest("testCachesDontUseAbsolutePaths"));
+        
         return suite;
     }
 
@@ -110,8 +119,6 @@
         }
         FileObject fo = FileUtil.getConfigFile("Services/Browsers");
         fo.delete();
-        // will be reset next time the system starts
-        System.getProperties().remove("netbeans.dirs");
         // initializes counting, but waits till netbeans.dirs are provided
         // by NbModuleSuite
         initCheckReadAccess();
@@ -139,5 +146,46 @@
             throw e;
         }
     }
+    
+    public void testRememberCacheDir() {
+        File cacheDir = Places.getCacheDirectory();
+        assertTrue("It is a directory", cacheDir.isDirectory());
+        System.setProperty("mycache", cacheDir.getPath());
+        
+        File boot = InstalledFileLocator.getDefault().locate("lib/boot.jar", "org.netbeans.bootstrap", false);
+        assertNotNull("Boot.jar found", boot);
+        System.setProperty("myinstall", boot.getParentFile().getParentFile().getParentFile().getPath());
+    }
 
+    public void testCachesDontUseAbsolutePaths() throws Exception {
+        String cache = System.getProperty("mycache");
+        String install = System.getProperty("myinstall");
+        
+        assertNotNull("Cache found", cache);
+        assertNotNull("Install found", install);
+        
+        File cacheDir = new File(cache);
+        assertTrue("Cache dir is dir", cacheDir.isDirectory());
+        int cnt = 0;
+        final File[] arr = cacheDir.listFiles();
+        Collections.shuffle(Arrays.asList(arr));
+        for (File f : arr) {
+            if (!f.isDirectory()) {
+                cnt++;
+                assertFileDoesNotContain(f, install);
+            }
+        }
+        assertTrue("Some cache files found", cnt > 4);
+    }
+
+    private static void assertFileDoesNotContain(File file, String text) throws IOException, PropertyVetoException {
+        LocalFileSystem lfs = new LocalFileSystem();
+        lfs.setRootDirectory(file.getParentFile());
+        FileObject fo = lfs.findResource(file.getName());
+        assertNotNull("file object for " + file + " found", fo);
+        String content = fo.asText();
+        if (content.contains(text)) {
+            fail("File " + file + " seems to contain '" + text + "'!");
+        }
+    }
 }
diff -r cc5360887ca1 o.n.bootstrap/src/org/netbeans/LocaleVariants.java
--- a/o.n.bootstrap/src/org/netbeans/LocaleVariants.java	Tue Feb 21 08:50:52 2012 +0100
+++ b/o.n.bootstrap/src/org/netbeans/LocaleVariants.java	Wed Feb 22 14:15:49 2012 +0100
@@ -72,7 +72,7 @@
             String locale = is.readUTF();
             mapLocale = Locale.getDefault().toString().equals(locale) ? Locale.getDefault() : null;
             for (;;) {
-                String file = is.readUTF();
+                String file = readRelativePath(is);
                 if (file.length() == 0) {
                     break;
                 }
@@ -100,7 +100,7 @@
         synchronized (map) {
             os.writeUTF(mapLocale.toString());
             for (Map.Entry<File, List<FileWithSuffix>> entry : map.entrySet()) {
-                os.writeUTF(entry.getKey().getPath());
+                writeRelativePath(entry.getKey(), os);
                 for (FileWithSuffix fws : entry.getValue()) {
                     fws.write(os);
                 }
@@ -131,6 +131,53 @@
         return l;
     }
 
+    private static void writeRelativePath(File path, DataOutputStream dos) 
+    throws IOException {
+        if (testWritePath(path, System.getProperty("netbeans.user"), "user", dos)) {
+            return;
+        }
+        int cnt = 0;
+        for (String p : System.getProperty("netbeans.dirs").split(File.pathSeparator)) {
+            if (testWritePath(path, p, "" + cnt, dos)) {
+                return;
+            }
+            cnt++;
+        }
+        if (testWritePath(path, System.getProperty("netbeans.home"), "home", dos)) {
+            return;
+        }
+        throw new IOException("Can't find relative path for " + path); // NOI18N
+    }
+    
+    private static String readRelativePath(DataInputStream dis) throws IOException {
+        String index = dis.readUTF();
+        if (index.isEmpty()) {
+            return index;
+        }
+        String relative = dis.readUTF();
+        if ("user".equals(index)) {
+            return System.getProperty("netbeans.user").concat(relative);
+        }
+        if ("home".equals(index)) {
+            return System.getProperty("netbeans.home").concat(relative);
+        }
+        int indx = Integer.parseInt(index);
+        return System.getProperty("netbeans.dirs").split(File.pathSeparator)[indx].concat(relative);
+    }
+
+    private static boolean testWritePath(File path, String prefix, String codeName, DataOutputStream dos) throws IOException {
+        if (prefix == null || prefix.isEmpty()) {
+            return false;
+        }
+        if (path.getPath().startsWith(prefix)) {
+            dos.writeUTF(codeName);
+            dos.writeUTF(path.getPath().substring(prefix.length()));
+            return true;
+        }
+        return false;
+    }
+
+
     static final class FileWithSuffix {
         public final File file;
         public final String suffix;
@@ -140,7 +187,7 @@
         }
 
         static FileWithSuffix read(DataInputStream is) throws IOException {
-            String path = is.readUTF();
+            String path = readRelativePath(is);
             if (path.length() == 0) {
                 return null;
             }
@@ -149,7 +196,7 @@
         }
 
         void write(DataOutputStream os) throws IOException {
-            os.writeUTF(file.getPath());
+            writeRelativePath(file, os);
             os.writeUTF(suffix);
         }
     }