diff --git a/src/com/android/settings/SettingsPreferenceFragment.java b/src/com/android/settings/SettingsPreferenceFragment.java
index 4796a9e..130137f 100644
--- a/src/com/android/settings/SettingsPreferenceFragment.java
+++ b/src/com/android/settings/SettingsPreferenceFragment.java
@@ -399,10 +399,11 @@
         for (Preference p : mPreferenceCache.values()) {
             group.removePreference(p);
         }
+        mPreferenceCache = null;
     }
 
     protected int getCachedCount() {
-        return mPreferenceCache.size();
+        return mPreferenceCache != null ? mPreferenceCache.size() : 0;
     }
 
     private void highlightPreference(String key) {