Index: app/code/core/Mage/Api/etc/api.xml
===================================================================
--- app/code/core/Mage/Api/etc/api.xml	(revision 37105)
+++ app/code/core/Mage/Api/etc/api.xml	(working copy)
@@ -69,6 +69,13 @@
         </resources>
         <resources_alias>
         </resources_alias>
+        <v2>
+            <wsdl>
+                <prefix>
+                    <wsdl>http://schemas.xmlsoap.org/wsdl/</wsdl>
+                </prefix>
+            </wsdl>
+        </v2>
         <faults>
             <unknown>
                 <code>0</code>
Index: app/code/core/Mage/Api/Model/Wsdl/Config.php
===================================================================
--- app/code/core/Mage/Api/Model/Wsdl/Config.php	(revision 37105)
+++ app/code/core/Mage/Api/Model/Wsdl/Config.php	(working copy)
@@ -33,9 +33,8 @@
  */
 class Mage_Api_Model_Wsdl_Config extends Mage_Api_Model_Wsdl_Config_Base
 {
+    protected static $_namespacesPrefix = null;
 
-    protected $_wsdlContent = null;
-
     public function __construct($sourceData=null)
     {
         $this->setCacheId('wsdl_config_global');
@@ -43,25 +42,30 @@
     }
 
     /**
-     * Set content of wsdl file as string
+     * Return wsdl content
      *
-     * @param string $wsdlContent
-     * @return Mage_Api_Model_Wsdl_Config
+     * @return string
      */
-    public function setWsdlContent($wsdlContent)
+    public function getWsdlContent()
     {
-        $this->_wsdlContent = $wsdlContent;
-        return $this;
+        return $this->_xml->asXML();
     }
 
     /**
-     * Return wsdl content
+     * Return namespaces with their prefix
      *
-     * @return string
+     * @return array
      */
-    public function getWsdlContent()
+    public static function getNamespacesPrefix()
     {
-        return $this->_wsdlContent;
+        if (is_null(self::$_namespacesPrefix)) {
+            self::$_namespacesPrefix = array();
+            $config = Mage::getConfig()->getNode('api/v2/wsdl/prefix')->children();
+            foreach ($config as $prefix => $namespace) {
+                self::$_namespacesPrefix[$namespace->asArray()] = $prefix;
+            }
+        }
+        return self::$_namespacesPrefix;
     }
 
     public function getCache()
@@ -105,12 +109,6 @@
                 BP . DS . 'app' . DS . 'code' . DS . 'community' . PS .
                 BP . DS . 'app' . DS . 'code' . DS . 'core' . PS .
                 BP . DS . 'lib' . PS .
-                /**
-                 * Problem with concatenate BP . $codeDir
-                 */
-                /*BP . $codeDir . DS .'community' . PS .
-                BP . $codeDir . DS .'core' . PS .
-                BP . $libDir . PS .*/
                 Mage::registry('original_include_path')
             );
         }
@@ -133,7 +131,6 @@
         $this->loadFile($baseWsdlFile);
 
         foreach ($modules as $modName=>$module) {
-//            if ($module->is('active') && $modName == 'Mage_Customer') {
             if ($module->is('active') && $modName != 'Mage_Api') {
                 if ($disableLocalModules && ('local' === (string)$module->codePool)) {
                     continue;
@@ -144,7 +141,6 @@
                 }
             }
         }
-        $this->setWsdlContent($this->_xml->asXML());
 
         if (Mage::app()->useCache('config')) {
             $this->saveCache(array('config'));
@@ -152,4 +148,14 @@
 
         return $this;
     }
+
+    /**
+     * Return Xml of node as string
+     *
+     * @return string
+     */
+    public function getXmlString()
+    {
+        return $this->getNode()->asXML();
+    }
 }
Index: app/code/core/Mage/Api/Model/Wsdl/Config/Element.php
===================================================================
--- app/code/core/Mage/Api/Model/Wsdl/Config/Element.php	(revision 37105)
+++ app/code/core/Mage/Api/Model/Wsdl/Config/Element.php	(working copy)
@@ -90,9 +90,13 @@
             $targetChild->setParent($this);
             foreach ($this->getAttributes($source) as $namespace => $attributes) {
                 foreach ($attributes as $key => $value) {
+                    $_namespacesPrefix = Mage_Api_Model_Wsdl_Config::getNamespacesPrefix();
                     if ($namespace == '') {
                         $namespace = null;
+                    } elseif (array_key_exists($namespace, $_namespacesPrefix)) {
+                        $key = $_namespacesPrefix[$namespace] . ':' . $key;
                     }
+
                     $targetChild->addAttribute($key, $this->xmlentities($value), $namespace);
                 }
             }
@@ -109,8 +113,11 @@
             $targetChild->setParent($this);
             foreach ($this->getAttributes($source) as $namespace => $attributes) {
                 foreach ($attributes as $key => $value) {
+                    $_namespacesPrefix = Mage_Api_Model_Wsdl_Config::getNamespacesPrefix();
                     if ($namespace == '') {
                         $namespace = null;
+                    } elseif (array_key_exists($namespace, $_namespacesPrefix)) {
+                        $key = $_namespacesPrefix[$namespace] . ':' . $key;
                     }
                     $targetChild->addAttribute($key, $this->xmlentities($value), $namespace);
                 }
@@ -169,7 +176,6 @@
         $children[''] = $source->children('');
         foreach ($namespaces as $key => $value) {
             if ($key == '' || $key == 'wsdl') {
-                $value = '';
                 continue;
             }
             $children[$value] = $source->children($value);
Index: lib/Varien/Simplexml/Config.php
===================================================================
--- lib/Varien/Simplexml/Config.php	(revision 37105)
+++ lib/Varien/Simplexml/Config.php	(working copy)
@@ -413,7 +413,7 @@
             $this->_saveCache($this->getCacheChecksum(), $this->getCacheChecksumId(), $tags, $this->getCacheLifetime());
         }
 
-        $xmlString = $this->getNode()->asNiceXml('', false);
+        $xmlString = $this->getXmlString();
         $this->_saveCache($xmlString, $this->getCacheId(), $tags, $this->getCacheLifetime());
 
         $this->setCacheSaved(true);
@@ -422,6 +422,16 @@
     }
 
     /**
+     * Return Xml of node as string
+     *
+     * @return string
+     */
+    public function getXmlString()
+    {
+        return $this->getNode()->asNiceXml('', false);
+    }
+
+    /**
      * Enter description here...
      *
      * @return Varien_Simplexml_Config