diff --git a/Classes/PHPExcel/CachedObjectStorageFactory.php b/Classes/PHPExcel/CachedObjectStorageFactory.php
index 0bda4ca..42d2f88 100644
--- a/Classes/PHPExcel/CachedObjectStorageFactory.php
+++ b/Classes/PHPExcel/CachedObjectStorageFactory.php
@@ -132,10 +132,7 @@ class PHPExcel_CachedObjectStorageFactory
 	 **/
 	public static function getCacheStorageMethod()
 	{
-		if (self::$_cacheStorageMethod !== NULL) {
-			return self::$_cacheStorageMethod;
-		}
-		return NULL;
+		return self::$_cacheStorageMethod;
 	}	//	function getCacheStorageMethod()
 
 
@@ -146,10 +143,7 @@ class PHPExcel_CachedObjectStorageFactory
 	 **/
 	public static function getCacheStorageClass()
 	{
-		if (self::$_cacheStorageClass !== NULL) {
-			return self::$_cacheStorageClass;
-		}
-		return NULL;
+		return self::$_cacheStorageClass;
 	}	//	function getCacheStorageClass()
 
 
diff --git a/Classes/PHPExcel/Settings.php b/Classes/PHPExcel/Settings.php
index a6c855d..e616231 100644
--- a/Classes/PHPExcel/Settings.php
+++ b/Classes/PHPExcel/Settings.php
@@ -142,7 +142,7 @@ class PHPExcel_Settings
 	 * @return	string				Name of the cacheing method
 	 */
 	public static function getCacheStorageMethod() {
-		return PHPExcel_CachedObjectStorageFactory::$_cacheStorageMethod;
+		return PHPExcel_CachedObjectStorageFactory::getCacheStorageMethod();
 	}	//	function getCacheStorageMethod()
 
 
@@ -152,7 +152,7 @@ class PHPExcel_Settings
 	 * @return	string				Name of the class currently being used for cacheing
 	 */
 	public static function getCacheStorageClass() {
-		return PHPExcel_CachedObjectStorageFactory::$_cacheStorageClass;
+		return PHPExcel_CachedObjectStorageFactory::getCacheStorageClass();
 	}	//	function getCacheStorageClass()
 
 
@@ -232,7 +232,7 @@ class PHPExcel_Settings
 	/**
 	 * Return the Chart Rendering Library that PHPExcel is currently configured to use (e.g. jpgraph)
 	 *
-	 * @return	 string						Internal reference name of the Chart Rendering Library that PHPExcel is
+	 * @return	 string|NULL				Internal reference name of the Chart Rendering Library that PHPExcel is
 	 *											currently configured to use
 	 *												e.g. PHPExcel_Settings::CHART_RENDERER_JPGRAPH
 	 */
@@ -244,7 +244,7 @@ class PHPExcel_Settings
 	/**
 	 * Return the directory path to the Chart Rendering Library that PHPExcel is currently configured to use
 	 *
-	 * @return	 string						Directory Path to the Chart Rendering Library that PHPExcel is
+	 * @return	 string|NULL				Directory Path to the Chart Rendering Library that PHPExcel is
 	 *											currently configured to use
 	 */
 	public static function getChartRendererPath() {
@@ -308,7 +308,7 @@ class PHPExcel_Settings
 	/**
 	 * Return the PDF Rendering Library that PHPExcel is currently configured to use (e.g. dompdf)
 	 *
-	 * @return	 string						Internal reference name of the PDF Rendering Library that PHPExcel is
+	 * @return	 string|NULL				Internal reference name of the PDF Rendering Library that PHPExcel is
 	 *											currently configured to use
 	 *												e.g. PHPExcel_Settings::PDF_RENDERER_TCPDF,
 	 *													 PHPExcel_Settings::PDF_RENDERER_DOMPDF
@@ -322,7 +322,7 @@ class PHPExcel_Settings
 	/**
 	 * Return the directory path to the PDF Rendering Library that PHPExcel is currently configured to use
 	 *
-	 * @return	 string						Directory Path to the PDF Rendering Library that PHPExcel is
+	 * @return	 string|NULL				Directory Path to the PDF Rendering Library that PHPExcel is
 	 *											currently configured to use
 	 */
 	public static function getPdfRendererPath() {
diff --git a/changelog.txt b/changelog.txt
index 0c777d2..fd7a73d 100644
--- a/changelog.txt
+++ b/changelog.txt
@@ -112,6 +112,8 @@ Fixed in develop branch:
 - Bugfix:   (dverspui)   Pattern fill colours in Excel2007 Style Writer
 - Bugfix:   (MBaker)     Excel2007 Writer order of font style elements to conform with Excel2003 using compatibility pack
 - Bugfix:   (MBaker)     Work item 18425 - Problems with $_activeSheetIndex when decreased below 0.
+- Bugfix:   (MBaker)     Work item 18597 - PHPExcel_CachedObjectStorage_SQLite3::cacheMethodIsAvailable() uses class_exists - autoloader throws error
+- Bugfix:   (MBaker)     Work item 18598 - Cannot access private property PHPExcel_CachedObjectStorageFactory::$_cacheStorageMethod
 
 
 2012-05-19 (v1.7.7):