--- t3lib/class.t3lib_befunc.php	2009-08-17 17:34:49.000000000 +0200
+++ t3lib/class.t3lib_befunc.php	2009-08-17 17:50:42.000000000 +0200
@@ -4029,7 +4029,7 @@
 	public static function displayWarningMessages() {
 		if ($GLOBALS['BE_USER']->isAdmin()) {
 			$warnings = array();	// Array containing warnings that must be displayed
-			$enableInstallToolFile = PATH_site.'typo3conf/ENABLE_INSTALL_TOOL';	// If this file exists, the Install Tool is enabled
+			$enableInstallToolFile = PATH_site.'typo3conf/ENABLE_INSTALL_TOOL';	// If this file exists, it doesn't contain the word "KEEP_FILE" and it isn't older than one hour, the Install Tool is enabled
 
 			$cmd = t3lib_div::_GET('adminWarning_cmd');	// Cleanup command, if set
 			switch($cmd) {
@@ -4062,7 +4062,9 @@
 			}
 			$GLOBALS['TYPO3_DB']->sql_free_result($res);
 
-			if (@is_file($enableInstallToolFile)) {
+			$content = file_get_contents($enableInstallToolFile);
+			$verifyString = 'KEEP_FILE';
+			if (trim($content) == $verifyString) {
 				$url = t3lib_div::getIndpEnv('TYPO3_REQUEST_SCRIPT').'?adminWarning_cmd=remove_ENABLE_INSTALL_TOOL';
 				$warnings['install_enabled'] = sprintf(
 					$GLOBALS['LANG']->sL('LLL:EXT:lang/locallang_core.xml:warning.install_enabled'),

--- typo3/sysext/lang/locallang_core.xml	2009-08-07 21:32:36.000000000 +0200
+++ typo3/sysext/lang/locallang_core.xml	2009-08-17 17:50:16.000000000 +0200
@@ -241,7 +241,7 @@
 			<label index="warning.backend_admin">The default backend user "admin" with password &quot;password&quot; is still present. %sEdit this account%s, either deleting it completely or changing the username and password.</label>
 			<label index="warning.file_deny_pattern">The value of fileDenyPattern is not set to its default:%s If TYPO3 is running on Apache, a customized value might enable backend or frontend users to execute malicious php scripts.</label>
 			<label index="warning.file_deny_htaccess">The current value of fileDenyPattern allows to upload/create files with the name ".htaccess". If TYPO3 is running on Apache, this enables backend or frontend users to create and execute php scripts. Please reset the value of fileDenyPattern to its default.</label>
-			<label index="warning.install_enabled">The Install Tool is enabled. Delete the file &quot;%s&quot; when you have finished setting up TYPO3.</label>
+			<label index="warning.install_enabled">The Install Tool is permanently enabled. Delete the file &quot;%s&quot; when you have finished setting up TYPO3.</label>
 			<label index="warning.install_enabled_cmd">Click to remove the file now!</label>
 			<label index="warning.install_encryption">The encryption key is not set. Set it in the %sBasic Configuration section%s of the Install Tool.</label>
 			<label index="warning.install_update">This installation is not configured for the TYPO3 version it is running. If you did so intentionally, this message can be safely ignored. If you are unsure, visit the %sUpdate Wizard%s section of the Install Tool to see how TYPO3 would change.</label>