diff --git a/ajax/documentController.php b/ajax/documentController.php
index a790b61c..42c657a9 100644
--- a/ajax/documentController.php
+++ b/ajax/documentController.php
@@ -51,16 +51,10 @@ class DocumentController extends Controller{
 	 * @param array $args - array containing session id as an element with a key es_id 
 	 */
 	public static function serve($args){
-		
 		$session = new Db_Session();
 		$sessionData = $session->load(@$args['es_id'])->getData();
 			
-		$file = new File(@$sessionData['file_id']);
-		if (!$file->isPublicShare()){
-			self::preDispatch();
-		} else {
-			self::preDispatchGuest();
-		}
+		self::preDispatchGuest();
 		
 		$filename = isset($sessionData['genesis_url']) ? $sessionData['genesis_url'] : '';
 		$download = new Download($sessionData['owner'], $filename);
diff --git a/ajax/otpoll.php b/ajax/otpoll.php
index 6a83f824..7a2d2e44 100644
--- a/ajax/otpoll.php
+++ b/ajax/otpoll.php
@@ -33,6 +33,16 @@ try{
 	
 	$session = new Db_Session();
 	$sessionData = $session->load($esId)->getData();
+	
+	$memberId = $request->getParam('args/member_id');
+	$member = new Db_Member();
+	$memberData = $member->load($memberId)->getData();
+	
+	if (isset($memberData['is_guest']) && $memberData['is_guest']){
+		Controller::preDispatchGuest(false);
+	} else {
+		Controller::preDispatch(false);
+	}
 
 	try {
 		$file = new File(@$sessionData['file_id']);
@@ -42,25 +52,18 @@ try{
 		$ex->setBody($request->getRawRequest());
 		throw $ex;
 	}
-	if (!$file->isPublicShare()){
-		Controller::preDispatch(false);
-	} else {
-		Controller::preDispatchGuest(false);
-	}
 	
 	$command = $request->getParam('command');
 	switch ($command){
 		case 'sync_ops':
 			$seqHead = (string) $request->getParam('args/seq_head');
 			if (!is_null($seqHead)){
-				$memberId = $request->getParam('args/member_id');
 				$ops = $request->getParam('args/client_ops');
 				$hasOps = is_array($ops) && count($ops)>0;
 
 				$op = new Db_Op();
 				$currentHead = $op->getHeadSeq($esId);
 				
-				$member = new Db_Member();
 				try {
 					$member->updateActivity($memberId);
 				} catch (\Exception $e){
diff --git a/ajax/sessionController.php b/ajax/sessionController.php
index 8cfcd219..51502570 100644
--- a/ajax/sessionController.php
+++ b/ajax/sessionController.php
@@ -22,8 +22,8 @@ class SessionController extends Controller{
 		
 		try {
 			$token = Helper::getArrayValueByKey($args, 'token');
-			$fileId = File::getIdByShareToken($token);
-			$session = Db_Session::start($uid, $fileId, true);
+			$file = File::getByShareToken($token);
+			$session = Db_Session::start($uid, $file, true);
 			\OCP\JSON::success($session);
 		} catch (\Exception $e){
 			Helper::warnLog('Starting a session failed. Reason: ' . $e->getMessage());
@@ -34,14 +34,15 @@ class SessionController extends Controller{
 
 	public static function joinAsUser($args){
 		$uid = self::preDispatch();
-		$fileId = intval(@$args['file_id']);
+		$fileId = Helper::getArrayValueByKey($args, 'file_id');
 		
 		try {
 			$view = \OC\Files\Filesystem::getView();
 			$path = $view->getPath($fileId);
 			
 			if ($view->isUpdatable($path)) {
-				$session = Db_Session::start($uid, $fileId, false);
+				$file = new File($fileId);
+				$session = Db_Session::start($uid, $file);
 				\OCP\JSON::success($session);
 			} else {
 				$info = $view->getFileInfo();
@@ -73,7 +74,8 @@ class SessionController extends Controller{
 			$currentMember = new Db_Member();
 			$currentMemberData = $currentMember->load($memberId)->getData();
 			if (isset($currentMemberData['is_guest']) && $currentMemberData['is_guest']){
-				self::preDispatchGuest();
+				$uid = self::preDispatchGuest();
+				$isGuest = true;				
 			} else {
 				self::preDispatch();
 			}
@@ -100,11 +102,14 @@ class SessionController extends Controller{
 			$sessionData = $session->getData();
 			try {
 				$file = new File($sessionData['file_id']);
+				if ($isGuest){
+					$file->setToken('yes');
+				}
+				
 				list($view, $path) = $file->getOwnerViewAndPath();
 			} catch (\Exception $e){
 				//File was deleted or unshared. We need to save content as new file anyway
 				//Sorry, but for guests it would be lost :(
-				$uid = self::preDispatch();
 				$view = new \OC\Files\View('/' . $uid . '/files');
 		
 				$dir = \OCP\Config::getUserValue(\OCP\User::getUser(), 'documents', 'save_path', '');
diff --git a/lib/db/session.php b/lib/db/session.php
index aa9bdff9..19f123da 100644
--- a/lib/db/session.php
+++ b/lib/db/session.php
@@ -35,9 +35,7 @@ class Db_Session extends \OCA\Documents\Db {
 	 * @return array
 	 * @throws \Exception
 	 */
-	public static function start($uid, $fileId, $isGuest){
-		
-		$file = new File($fileId);
+	public static function start($uid, $file){
 		// Create a directory to store genesis
 		$genesis = new Genesis($file);
 		
@@ -70,7 +68,7 @@ class Db_Session extends \OCA\Documents\Db {
 			$uid,
 			$memberColor,
 			time(),
-			intval($isGuest)
+			intval($file->isPublicShare())
 		));
 		
 		if ($member->insert()){
@@ -81,7 +79,7 @@ class Db_Session extends \OCA\Documents\Db {
 				$imageUrl = $uid;
 			}
 
-			$displayName = $isGuest ? $uid . ' ' . Db_Member::getGuestPostfix() : \OCP\User::getDisplayName($uid);
+			$displayName = $file->isPublicShare() ? $uid . ' ' . Db_Member::getGuestPostfix() : \OCP\User::getDisplayName($uid);
 			
 			$session['member_id'] = (string) $member->getLastInsertId();
 			$op = new Db_Op();
diff --git a/lib/file.php b/lib/file.php
index 0f132beb..c22b9533 100644
--- a/lib/file.php
+++ b/lib/file.php
@@ -28,6 +28,7 @@ class File {
 	protected $owner;
 	protected $path;
 	protected $sharing;
+	protected $token ='';
 	protected $passwordProtected = false;
 
 
@@ -47,22 +48,6 @@ class File {
 		}
 	}
 	
-	public static function getIdByShareToken($token){
-		$linkItem = \OCP\Share::getShareByToken($token, false);
-		if (is_array($linkItem) && isset($linkItem['uid_owner'])) {
-			// seems to be a valid share
-			$rootLinkItem = \OCP\Share::resolveReShare($linkItem);
-			$fileOwner = $rootLinkItem['uid_owner'];
-		} else {
-			throw new \Exception('This file was probably unshared');
-		}
-		
-		if (!isset($rootLinkItem['path']) && isset($rootLinkItem['file_target'])){
-			$rootLinkItem['path'] = $rootLinkItem['file_target'];
-		}
-		
-		return $rootLinkItem['file_source'];
-	}
 	
 	public static function getByShareToken($token){
 		$linkItem = \OCP\Share::getShareByToken($token, false);
@@ -78,7 +63,7 @@ class File {
 			$rootLinkItem['path'] = $rootLinkItem['file_target'];
 		}
 		$file = new File($rootLinkItem['file_source'], array($rootLinkItem));
-		
+		$file->setToken($token);
 
 		if (isset($rootLinkItem['uid_owner'])){
 			\OC_Util::tearDownFS();
@@ -106,16 +91,12 @@ class File {
 		$this->path = $path;
 	}
 	
+	public function setToken($token){
+		$this->token = $token;
+	}
+	
 	public function isPublicShare(){
-		foreach ($this->sharing as $share){
-			if (
-					$share['share_type'] == \OCP\Share::SHARE_TYPE_LINK 
-					|| $share['share_type'] == \OCP\Share::SHARE_TYPE_EMAIL
-				){
-				return true;
-			}
-		}
-		return false;
+		return  !empty($this->token);
 	}
 	
 	public function isPasswordProtected(){
@@ -217,11 +198,11 @@ class File {
 			} else {
 				$owner = false;
 			}
-			\OC_Util::tearDownFS();
-			\OC_Util::setupFS($owner);
+			$view = new View('/' . $owner . '/files');
+			
 			return array(
 					$owner,
-					\OC\Files\Filesystem::getPath($rootLinkItem['file_source'])
+					$view->getPath($rootLinkItem['file_source'])
                 );
 		}