Index: t3lib/formprotection/class.t3lib_formprotection_abstract.php
===================================================================
--- t3lib/formprotection/class.t3lib_formprotection_abstract.php	(revision 10383)
+++ t3lib/formprotection/class.t3lib_formprotection_abstract.php	(working copy)
@@ -56,6 +56,20 @@
 	protected $tokens = array();
 
 	/**
+	 * Tokens that have been added during this request.
+	 *
+	 * @var array<array>
+	 */
+	protected $addedTokens = array();
+
+	/**
+	 * Token ids of tokens that have been dropped during this request.
+	 *
+	 * @var array
+	 */
+	protected $droppedTokenIds = array();
+
+	/**
 	 * Constructor. Makes sure existing tokens are read and available for
 	 * checking.
 	 */
@@ -123,6 +137,7 @@
 			'action' => $action,
 			'formInstanceName' => $formInstanceName,
 		);
+		$this->addedTokens[$tokenId] = $this->tokens[$tokenId];
 		$this->preventOverflow();
 
 		return $tokenId;
@@ -219,10 +234,31 @@
 	protected function dropToken($tokenId) {
 		if (isset($this->tokens[$tokenId])) {
 			unset($this->tokens[$tokenId]);
+			$this->droppedTokenIds[] = $tokenId;
 		}
 	}
 
 	/**
+	 * Persisting of tokens is only required, if tokens are
+	 * deleted or added during this request.
+	 *
+	 * @return boolean
+	 */
+	protected function isPersistingRequired() {
+		return !empty($this->droppedTokenIds) || !empty($this->addedTokens);
+	}
+
+	/**
+	 * Reset the arrays of added or deleted tokens.
+	 *
+	 * @return void
+	 */
+	protected function resetPersistingRequiredStatus() {
+		$this->droppedTokenIds = array();
+		$this->addedTokens = array();
+	}
+
+	/**
 	 * Checks whether the number of current tokens still is at most
 	 * $this->maximumNumberOfTokens.
 	 *
Index: t3lib/formprotection/class.t3lib_formprotection_backendformprotection.php
===================================================================
--- t3lib/formprotection/class.t3lib_formprotection_backendformprotection.php	(revision 10383)
+++ t3lib/formprotection/class.t3lib_formprotection_backendformprotection.php	(working copy)
@@ -139,6 +139,19 @@
 	}
 
 	/**
+	 * Overrule the method in the absract class, because we can drop the
+	 * whole locking procedure, which is done in persistTokens, if we
+	 * simply want to delete all tokens.
+	 *
+	 * @see t3lib/formprotection/t3lib_formprotection_Abstract::clean()
+	 */
+	public function clean() {
+		$this->tokens = array();
+		$this->backendUser->setAndSaveSessionData('formTokens', $this->tokens);
+		$this->resetPersistingRequiredStatus();
+	}
+
+	/**
 	 * Creates or displayes an error message telling the user that the submitted
 	 * form token is invalid.
 	 *
@@ -184,7 +197,10 @@
 	protected function updateTokens() {
 		$this->backendUser->user = $this->backendUser->fetchUserSession(TRUE);
 		$tokens = $this->retrieveTokens();
-		$this->tokens = array_merge($this->tokens, $tokens);
+		$this->tokens = array_merge($tokens, $this->addedTokens);
+		foreach ($this->droppedTokenIds as $tokenId) {
+			unset($this->tokens[$tokenId]);
+		}
 	}
 
 	/**
@@ -194,12 +210,15 @@
 	 * @return void
 	 */
 	public function persistTokens() {
-		$lockObject = $this->acquireLock();
+		if ($this->isPersistingRequired()) {
+			$lockObject = $this->acquireLock();
 
-		$this->updateTokens();
-		$this->backendUser->setAndSaveSessionData('formTokens', $this->tokens);
+			$this->updateTokens();
+			$this->backendUser->setAndSaveSessionData('formTokens', $this->tokens);
+			$this->resetPersistingRequiredStatus();
 
-		$this->releaseLock($lockObject);
+			$this->releaseLock($lockObject);
+		}
 	}
 
 	/**