diff --git a/actions/admin/settings/120.system.php b/actions/admin/settings/120.system.php
index b9891344..8b87656b 100644
--- a/actions/admin/settings/120.system.php
+++ b/actions/admin/settings/120.system.php
@@ -28,6 +28,7 @@ return array(
 					'varname' => 'documentroot_prefix',
 					'type' => 'string',
 					'default' => '/var/customers/webs/',
+					'plausibility_check_method' => 'checkPathConflicts',
 					'save_method' => 'storeSettingField',
 					),
 				'system_ipaddress' => array(
diff --git a/actions/admin/settings/135.fcgid.php b/actions/admin/settings/135.fcgid.php
index e225dc7d..982288e8 100644
--- a/actions/admin/settings/135.fcgid.php
+++ b/actions/admin/settings/135.fcgid.php
@@ -36,6 +36,7 @@ return array(
 					'type' => 'string',
 					'string_type' => 'dir',
 					'default' => '/var/www/php-fcgi-scripts/',
+					'plausibility_check_method' => 'checkPathConflicts',
 					'save_method' => 'storeSettingField',
 					),
 				'system_mod_fcgid_tmpdir' => array(
diff --git a/lib/functions/validate/function.checkPathConflicts.php b/lib/functions/validate/function.checkPathConflicts.php
new file mode 100644
index 00000000..30800bbd
--- /dev/null
+++ b/lib/functions/validate/function.checkPathConflicts.php
@@ -0,0 +1,60 @@
+<?php
+
+/**
+ * This file is part of the Froxlor project.
+ * Copyright (c) 2010 the Froxlor Team (see authors).
+ *
+ * For the full copyright and license information, please view the COPYING
+ * file that was distributed with this source code. You can also view the
+ * COPYING file online at http://files.froxlor.org/misc/COPYING.txt
+ *
+ * @copyright  (c) the authors
+ * @author     Froxlor team <team@froxlor.org> (2010-)
+ * @license    GPLv2 http://files.froxlor.org/misc/COPYING.txt
+ * @package    Functions
+ * @version    $Id$
+ */
+
+function checkPathConflicts($fieldname, $fielddata, $newfieldvalue, $allnewfieldvalues)
+{
+	global $settings;
+	if((int)$settings['system']['mod_fcgid'] == 1)
+	{
+		/**
+		 * fcgid-configdir has changed ->
+		 * check against customer-doc-prefix
+		 */
+		if($fieldname == "system_mod_fcgid_configdir") 
+		{
+			$newdir = makeCorrectDir($newfieldvalue);
+			$cdir = makeCorrectDir($settings['system']['documentroot_prefix']);
+		}
+		/**
+		 * customer-doc-prefix has changed ->
+		 * check against fcgid-configdir
+		 */
+		elseif($fieldname == "system_documentroot_prefix")
+		{
+			$newdir = makeCorrectDir($newfieldvalue);
+			$cdir = makeCorrectDir($settings['system']['mod_fcgid_configdir']);
+		}
+
+		// neither dir can be within the other nor can they be equal
+		if(substr($newdir, 0, strlen($cdir)) == $cdir
+			|| substr($cdir, 0, strlen($newdir)) == $newdir
+			|| $newdir == $cdir
+		) {
+			$returnvalue = array(FORMFIELDS_PLAUSIBILITY_CHECK_ERROR, 'fcgidpathcannotbeincustomerdoc');
+		}
+		else
+		{
+			$returnvalue = array(FORMFIELDS_PLAUSIBILITY_CHECK_OK);
+		}
+	}
+	else
+	{
+		$returnvalue = array(FORMFIELDS_PLAUSIBILITY_CHECK_OK);
+	}
+
+	return $returnvalue;
+}