Index: trunk/core/kernel/utility/unit_config_reader.php
===================================================================
diff -u -r4845 -r4864
--- trunk/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 4845)
+++ trunk/core/kernel/utility/unit_config_reader.php	(.../unit_config_reader.php)	(revision 4864)
@@ -120,14 +120,19 @@
 
 	function scanModules($folderPath, $cache = true)
 	{
-		if (!defined('IS_INSTALL') && $cache) {
+		if (defined('IS_INSTALL') && IS_INSTALL) {
+			// disable config caching during installation
+			$cache = false;
+		}
+		
+		if ($cache) {
 			$restored = $this->RestoreParsedData();
 			if ($restored) return;
 		}
 
 		$this->ProcessAllConfigs = true;
 
-		$this->includeConfigFiles($folderPaths, $cache);
+		$this->includeConfigFiles($folderPath, $cache);
 		$this->ParseConfigs();
 
 		$this->CacheParsedData();
@@ -146,13 +151,11 @@
 		$reg_exp = '/^'.preg_quote(FULL_PATH, '/').'/';
 		$folderPath = preg_replace($reg_exp, '', $folderPath, 1); // this make sense, since $folderPath may NOT contain FULL_PATH
 
-		$fh=opendir(FULL_PATH.$folderPath);
-		while(($sub_folder=readdir($fh)))
-		{
+		$fh = opendir(FULL_PATH.$folderPath);
+		while (($sub_folder = readdir($fh))) {
 			$full_path = FULL_PATH.$folderPath.'/'.$sub_folder;
-			if( $this->isDir($full_path))
-			{
-				if ( file_exists(FULL_PATH.$this->getConfigName($folderPath.'/'.$sub_folder)) ) {
+			if ($this->isDir($full_path)) {
+				if (file_exists(FULL_PATH.$this->getConfigName($folderPath.'/'.$sub_folder))) {
 					$this->configFiles[] = $this->getConfigName($folderPath.'/'.$sub_folder);
 				}
 				$this->findConfigFiles($full_path);
@@ -163,7 +166,7 @@
 		}
 	}
 
-	function includeConfigFiles($folderPath, $cache=true)
+	function includeConfigFiles($folderPath, $cache = true)
 	{
 		$this->Application->refreshModuleInfo();
 
@@ -426,16 +429,23 @@
 			if($config_found) include_once(FULL_PATH.$filename);
 		}
 
-		if($config_found && isset($config) && $config)
-		{
-			$prefix = isset($config['Prefix']) ? $config['Prefix'] : '';
-
-			preg_match('/\/(.*)\//U', $filename, $rets);
-			$config['ModuleFolder'] = $rets[1];
-			$config['BasePath'] = dirname(FULL_PATH.$filename);
-			$this->configData[$prefix] = $config;
-			$this->prefixFiles[$prefix] = $filename;
-			return $prefix;
+		if ($config_found) {
+			if (isset($config) && $config) {
+				// config file is included for 1st time -> save it's content for future processing
+				$prefix = isset($config['Prefix']) ? $config['Prefix'] : '';
+	
+				preg_match('/\/(.*)\//U', $filename, $rets);
+				$config['ModuleFolder'] = $rets[1];
+				$config['BasePath'] = dirname(FULL_PATH.$filename);
+				$this->configData[$prefix] = $config;
+				$this->prefixFiles[$prefix] = $filename;
+				return $prefix;
+			}
+			elseif ($prefix = array_search($filename, $this->prefixFiles)) {
+				// attempt is made to include config file twice or more, but include_once prevents that,
+				// but file exists on hdd, then it is already saved to all required arrays, just return it's prefix
+				return $prefix;
+			}
 		}
 		return 'dummy';
 	}