diff --git a/src/Zend/Io/Reader.php b/src/Zend/Io/Reader.php
index 8170052..444b98b 100644
--- a/src/Zend/Io/Reader.php
+++ b/src/Zend/Io/Reader.php
@@ -570,7 +570,11 @@ class Zend_Io_Reader
             }
         }
 
-        return substr($value, -2) == "\0\0" ? substr($value, 0, -2) : $value;
+        while (substr($value, -2) == "\0\0") {
+            $value = substr($value, 0, -2);
+        }
+
+        return $value;
     }
 
     /**
diff --git a/src/Zend/Io/StringWriter.php b/src/Zend/Io/StringWriter.php
index 6ce98b7..b743a2f 100644
--- a/src/Zend/Io/StringWriter.php
+++ b/src/Zend/Io/StringWriter.php
@@ -69,6 +69,9 @@ class Zend_Io_StringWriter extends Zend_Io_Writer
      */
     public function toString()
     {
+        if ($this->getSize() == 0) {
+            return '';
+        }
         $offset = $this->getOffset();
         $this->setOffset(0);
         $data = fread($this->getFileDescriptor(), $this->getSize());
diff --git a/src/Zend/Io/Writer.php b/src/Zend/Io/Writer.php
index 1de4c75..9359f7c 100644
--- a/src/Zend/Io/Writer.php
+++ b/src/Zend/Io/Writer.php
@@ -492,7 +492,7 @@ class Zend_Io_Writer
      * @throws Zend_Io_Exception if <var>length</var> attribute is negative or
      *  if the stream is closed
      */
-    public final function writeHHex($length)
+    public final function writeHHex($value)
     {
         return $this->write(pack('H*', $value));
     }
@@ -506,7 +506,7 @@ class Zend_Io_Writer
      * @throws Zend_Io_Exception if <var>length</var> attribute is negative or
      *  if the stream is closed
      */
-    public final function writeLHex($length)
+    public final function writeLHex($value)
     {
         return $this->write(pack('h*', $value));
     }
@@ -519,7 +519,7 @@ class Zend_Io_Writer
      * @return Zend_Io_Writer
      * @throws Zend_Io_Exception if the stream is closed
      */
-    public final function writeGuid()
+    public final function writeGuid($value)
     {
         $string = '';
         $C = preg_split('/-/', $value);