diff --git a/mtp/btree.cpp b/mtp/btree.cpp
index e53afab..b73789b 100755
--- a/mtp/btree.cpp
+++ b/mtp/btree.cpp
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-#include <iostream>
 #include <utils/threads.h>
 #include "btree.hpp"
 #include "MtpDebug.h"
@@ -60,7 +59,7 @@
 }
 
 Node* Tree::findNode(MtpObjectHandle handle) {
-	std::map<MtpObjectHandle, Node*>::iterator it = entries.find(handle);	
+	std::map<MtpObjectHandle, Node*>::iterator it = entries.find(handle);
 	if (it != entries.end())
 		return it->second;
 	return NULL;
@@ -72,7 +71,7 @@
 }
 
 void Tree::deleteNode(MtpObjectHandle handle) {
-	std::map<MtpObjectHandle, Node*>::iterator it = entries.find(handle);	
+	std::map<MtpObjectHandle, Node*>::iterator it = entries.find(handle);
 	if (it != entries.end()) {
 		delete it->second;
 		entries.erase(it);
diff --git a/mtp/btree.hpp b/mtp/btree.hpp
index b284e4f..e1aad36 100755
--- a/mtp/btree.hpp
+++ b/mtp/btree.hpp
@@ -18,6 +18,7 @@
 #define BTREE_HPP
 
 #include <vector>
+#include <string>
 #include <map>
 #include "MtpTypes.h"
 
diff --git a/mtp/node.cpp b/mtp/node.cpp
index 1bca1d9..207a37a 100755
--- a/mtp/node.cpp
+++ b/mtp/node.cpp
@@ -14,9 +14,7 @@
  * limitations under the License.
  */
 
-#include <iostream>
 #include <vector>
-#include <sstream>
 #include <sys/stat.h>
 #include <sys/statfs.h>
 #include <sys/types.h>
@@ -103,13 +101,9 @@
 	MTPD("addProperties: handle: %u, filename: '%s'\n", handle, getName().c_str());
 	struct stat st;
 	int mFormat = 0;
-	uint64_t puid;
+	uint64_t puid = ((uint64_t)storageID << 32) + handle;
 	off_t file_size = 0;
 
-	std::string mtpidStr = static_cast<std::ostringstream*>( &(std::ostringstream() << handle) )->str();
-	std::string storageIDStr = static_cast<std::ostringstream*>( &(std::ostringstream() << storageID) )->str();
-	std::string puidStr = storageIDStr + mtpidStr;
-	if ( ! (std::istringstream(puidStr) >> puid) ) puid = 0;
 	mFormat = MTP_FORMAT_UNDEFINED;   // file
 	if (lstat(path.c_str(), &st) == 0) {
 		file_size = st.st_size;
@@ -129,6 +123,7 @@
 		// TODO: we can't really support persistent UIDs without a persistent DB.
 		// probably a combination of volume UUID + st_ino would come close.
 		// doesn't help for fs with no native inodes numbers like fat though...
+		// however, Microsoft's own impl (Zune, etc.) does not support persistent UIDs either
 	addProperty(MTP_PROPERTY_NAME, 0, getName().c_str(), MTP_TYPE_STR);
 	addProperty(MTP_PROPERTY_DISPLAY_NAME, 0, getName().c_str(), MTP_TYPE_STR);
 	addProperty(MTP_PROPERTY_DATE_ADDED, st.st_mtime, "", MTP_TYPE_UINT64);