Index: typo3/sysext/cms/tslib/class.tslib_fe.php
===================================================================
--- typo3/sysext/cms/tslib/class.tslib_fe.php	(revision 2937)
+++ typo3/sysext/cms/tslib/class.tslib_fe.php	(working copy)
@@ -3725,11 +3725,17 @@
 	/**
 	 * Substitutes all occurencies of <a href="#"... in $this->content with <a href="[path-to-url]#"...
 	 *
-	 * @return	void		Works directly on $this->content
+	 * @return	void		The substituted content.
 	 */
 	function prefixLocalAnchorsWithScript()	{
 		$scriptPath = substr(t3lib_div::getIndpEnv('TYPO3_REQUEST_URL'),strlen(t3lib_div::getIndpEnv('TYPO3_SITE_URL')));
-		$this->content = preg_replace('/(<(a|area).*?href=")(#[^"]*")/i','${1}' . htmlspecialchars($scriptPath) . '${3}',$this->content);
+		$original_content = $this->content;
+		$this->content = preg_replace('/(<(a|area).+href=")(#[^"]*")/i','${1}' . htmlspecialchars($scriptPath) . '${3}',$original_content);
+		if(preg_last_error()>0) {
+				//The was an error in call to preg_replace, so keep original content (Behavior prior t PHP 5.2).
+			t3lib_div::sysLog('preg_replace returned error-code: ' . preg_last_error().' in function prefixLocalAnchorsWithScript. Replacement not done!' , 'cms', 4);	
+			$this->content = $original_content;	
+		}
 	}
 
 	/**