diff -ru typo3_old/sysext/setup/mod/index.php typo3/sysext/setup/mod/index.php
--- typo3_old/sysext/setup/mod/index.php	2010-02-25 00:27:08.000000000 -0500
+++ typo3/sysext/setup/mod/index.php	2010-02-25 01:18:14.000000000 -0500
@@ -115,6 +115,7 @@
 	protected $passwordIsUpdated = FALSE;
 	protected $passwordIsSubmitted = FALSE;
 	protected $setupIsUpdated = FALSE;
+	protected $tempDataCleared = FALSE;
 
 
 	/******************************
@@ -130,7 +131,7 @@
 	 * @return	void
 	 */
 	function storeIncomingData()	{
-		global $BE_USER;
+		global $BE_USER,$LANG;
 
 			// First check if something is submittet in the data-array from POST vars
 		$d = t3lib_div::_POST('data');
@@ -159,6 +160,7 @@
 						unset ($BE_USER->uc[$key]);
 					}
 				}
+				$this->tempDataCleared = TRUE;
 			} else {
 					// save all submitted values if they are no array (arrays are with table=be_users) and exists in $GLOBALS['TYPO3_USER_SETTINGS'][columns]
 				foreach($columns as $field => $config) {
@@ -180,11 +182,14 @@
 			$BE_USER->overrideUC();	// Inserts the overriding values.
 
 			$save_after = md5(serialize($BE_USER->uc));
-			if ($save_before!=$save_after)	{	// If something in the uc-array of the user has changed, we save the array...
+			if ($save_before!=$save_after && !$this->tempDataCleared)	{	// If something in the uc-array of the user has changed, we save the array...
 				$BE_USER->writeUC($BE_USER->uc);
 				$BE_USER->writelog(254, 1, 0, 1, 'Personal settings changed', array());
 				$this->setupIsUpdated = TRUE;
 			}
+			if ($this->tempDataCleared) { //If the temporary data has been cleared, lets make a log note about it
+				$BE_USER->writelog(254, 1, 0, 1, $LANG->getLL('tempDataClearedLog'), array());
+			}
 
 
 				// Personal data for the users be_user-record (email, name, password...)
@@ -334,6 +339,15 @@
 			);
 			$this->content .= $flashMessage->render();
 		}
+			// Show if temporary data was cleared
+		if ($this->tempDataCleared) {
+			$flashMessage = t3lib_div::makeInstance(
+				't3lib_FlashMessage',
+				$LANG->getLL('tempDataClearedFlashMessage'),
+				$LANG->getLL('tempDataCleared')
+			);
+			$this->content .= $flashMessage->render();
+		}
 			// If password is updated, output whether it failed or was OK.
 		if ($this->passwordIsSubmitted) {
 			if ($this->passwordIsUpdated) {
diff -ru typo3_old/sysext/setup/mod/locallang.xml typo3/sysext/setup/mod/locallang.xml
--- typo3_old/sysext/setup/mod/locallang.xml	2010-02-25 00:27:08.000000000 -0500
+++ typo3/sysext/setup/mod/locallang.xml	2010-02-25 01:20:47.000000000 -0500
@@ -89,7 +89,7 @@
 			<label index="resetConfiguration">Reset Configuration and Clear Temporary Data</label>
 			<label index="setToStandardQuestion">Are you sure you want to reset all values to default?</label>
 			<label index="clearSessionVars">Clear Temporary Data</label>
-                        <label index="clearSessionVarsQuestion">Are you sure you want to clear temporary data?</label>
+			<label index="clearSessionVarsQuestion">Are you sure you want to clear temporary data?</label>
 			<label index="functions">Advanced functions</label>
 			<label index="copyLevels">&lt;b&gt;Recursive Copy:&lt;/b&gt; Enter the number of page&lt;br /&gt;sublevels to include, when a page is copied</label>
 			<label index="recursiveDelete">&lt;b&gt;Recursive Delete(!):&lt;/b&gt; Allow ALL subpages&lt;br /&gt;to be deleted when deleting a page</label>
@@ -107,6 +107,9 @@
 			<label index="enableInstallTool.label">Install Tool Access</label>
 			<label index="enableInstallTool.createFile">Create Install Tool Enable File</label>
 			<label index="enableInstallTool.deleteFile">Delete Install Tool Enable File</label>
+			<label index="tempDataCleared">Temporary data cleared</label>
+			<label index="tempDataClearedFlashMessage">The temporary data has been cleared</label>
+			<label index="tempDataClearedLog">Temporary data cleared</label>
 		</languageKey>
 	</data>
 </T3locallang>
Only in typo3/sysext/setup/mod/: .svn