diff --git a/Classes/PHPExcel/ReferenceHelper.php b/Classes/PHPExcel/ReferenceHelper.php
index 8b986c0..5b17054 100644
--- a/Classes/PHPExcel/ReferenceHelper.php
+++ b/Classes/PHPExcel/ReferenceHelper.php
@@ -68,7 +68,15 @@ class PHPExcel_ReferenceHelper
 	protected function __construct() {
 	}
 
-	private function cellSort($a, $b) {
+	public static function columnSort($a, $b) {
+		return strcasecmp(strlen($a) . $a, strlen($b) . $b);
+	}
+
+	public static function columnReverseSort($a, $b) {
+		return 1 - strcasecmp(strlen($a) . $a, strlen($b) . $b);
+	}
+
+	public static function cellSort($a, $b) {
 		list($ac,$ar) = sscanf($a,'%[A-Z]%d');
 		list($bc,$br) = sscanf($b,'%[A-Z]%d');
 
@@ -78,7 +86,7 @@ class PHPExcel_ReferenceHelper
 		return ($ar < $br) ? -1 : 1;
 	}
 
-	private function cellReverseSort($a, $b) {
+	public static function cellReverseSort($a, $b) {
 		list($ac,$ar) = sscanf($a,'%[A-Z]%d');
 		list($bc,$br) = sscanf($b,'%[A-Z]%d');
 
@@ -270,14 +278,14 @@ class PHPExcel_ReferenceHelper
 
 		// Update worksheet: breaks
 		$aBreaks = $pSheet->getBreaks();
-		($pNumCols > 0 || $pNumRows > 0) ? 
-			uksort($aBreaks, array('PHPExcel_ReferenceHelper','cellReverseSort')) : 
-			uksort($aBreaks, array('PHPExcel_ReferenceHelper','cellSort')); 
+		($pNumCols > 0 || $pNumRows > 0) ?
+			uksort($aBreaks, array('PHPExcel_ReferenceHelper','cellReverseSort')) :
+			uksort($aBreaks, array('PHPExcel_ReferenceHelper','cellSort'));
 		foreach ($aBreaks as $key => $value) {
 			$newReference = $this->updateCellReference($key, $pBefore, $pNumCols, $pNumRows);
 			if ($key != $newReference) {
-				$pSheet->setBreak( $newReference, $value );
-				$pSheet->setBreak( $key, PHPExcel_Worksheet::BREAK_NONE );
+				$pSheet->setBreak($newReference, $value)
+				    ->setBreak($key, PHPExcel_Worksheet::BREAK_NONE);
 			}
 		}
 
@@ -292,9 +300,9 @@ class PHPExcel_ReferenceHelper
 
 		// Update worksheet: hyperlinks
 		$aHyperlinkCollection = $pSheet->getHyperlinkCollection();
-		($pNumCols > 0 || $pNumRows > 0) ? 
-			uksort($aHyperlinkCollection, array('PHPExcel_ReferenceHelper','cellReverseSort')) : 
-			uksort($aHyperlinkCollection, array('PHPExcel_ReferenceHelper','cellSort')); 
+		($pNumCols > 0 || $pNumRows > 0) ?
+			uksort($aHyperlinkCollection, array('PHPExcel_ReferenceHelper','cellReverseSort')) :
+			uksort($aHyperlinkCollection, array('PHPExcel_ReferenceHelper','cellSort'));
 		foreach ($aHyperlinkCollection as $key => $value) {
 			$newReference = $this->updateCellReference($key, $pBefore, $pNumCols, $pNumRows);
 			if ($key != $newReference) {
@@ -305,9 +313,9 @@ class PHPExcel_ReferenceHelper
 
 		// Update worksheet: data validations
 		$aDataValidationCollection = $pSheet->getDataValidationCollection();
-		($pNumCols > 0 || $pNumRows > 0) ? 
-			uksort($aDataValidationCollection, array('PHPExcel_ReferenceHelper','cellReverseSort')) : 
-			uksort($aDataValidationCollection, array('PHPExcel_ReferenceHelper','cellSort')); 
+		($pNumCols > 0 || $pNumRows > 0) ?
+			uksort($aDataValidationCollection, array('PHPExcel_ReferenceHelper','cellReverseSort')) :
+			uksort($aDataValidationCollection, array('PHPExcel_ReferenceHelper','cellSort'));
 		foreach ($aDataValidationCollection as $key => $value) {
 			$newReference = $this->updateCellReference($key, $pBefore, $pNumCols, $pNumRows);
 			if ($key != $newReference) {
@@ -327,9 +335,9 @@ class PHPExcel_ReferenceHelper
 
 		// Update worksheet: protected cells
 		$aProtectedCells = $pSheet->getProtectedCells();
-		($pNumCols > 0 || $pNumRows > 0) ? 
-			uksort($aProtectedCells, array('PHPExcel_ReferenceHelper','cellReverseSort')) : 
-			uksort($aProtectedCells, array('PHPExcel_ReferenceHelper','cellSort')); 
+		($pNumCols > 0 || $pNumRows > 0) ?
+			uksort($aProtectedCells, array('PHPExcel_ReferenceHelper','cellReverseSort')) :
+			uksort($aProtectedCells, array('PHPExcel_ReferenceHelper','cellSort'));
 		foreach ($aProtectedCells as $key => $value) {
 			$newReference = $this->updateCellReference($key, $pBefore, $pNumCols, $pNumRows);
 			if ($key != $newReference) {
diff --git a/Classes/PHPExcel/Worksheet.php b/Classes/PHPExcel/Worksheet.php
index 9791ead..51cb4e7 100644
--- a/Classes/PHPExcel/Worksheet.php
+++ b/Classes/PHPExcel/Worksheet.php
@@ -1604,7 +1604,13 @@ class PHPExcel_Worksheet implements PHPExcel_IComparable
         $pCell = strtoupper($pCell);
 
         if ($pCell != '') {
-            $this->_breaks[$pCell] = $pBreak;
+        	if ($pBreak == PHPExcel_Worksheet::BREAK_NONE) {
+        		if (isset($this->_breaks[$pCell])) {
+	            	unset($this->_breaks[$pCell]);
+        		}
+        	} else {
+	            $this->_breaks[$pCell] = $pBreak;
+	        }
         } else {
             throw new PHPExcel_Exception('No cell coordinate specified.');
         }
@@ -2432,9 +2438,9 @@ class PHPExcel_Worksheet implements PHPExcel_IComparable
                         if ($formatData) {
                             $style = $this->_parent->getCellXfByIndex($cell->getXfIndex());
                             $returnValue[$rRef][$cRef] = PHPExcel_Style_NumberFormat::toFormattedString(
-                            	$returnValue[$rRef][$cRef], 
-								($style->getNumberFormat()) ? 
-									$style->getNumberFormat()->getFormatCode() : 
+                            	$returnValue[$rRef][$cRef],
+								($style->getNumberFormat()) ?
+									$style->getNumberFormat()->getFormatCode() :
 									PHPExcel_Style_NumberFormat::FORMAT_GENERAL
                             );
                         }