Installationsfehler: fopen(../config.php)

Hallo,

ich versuche gerade 2.7 auf einem windows 2003 server zu installieren (v-host unter plesk). obwohl alle angaben auf der installationsseite grün sind,
Step 1
Please check the following requirements are met before continuing...
PHP Version > 4.1.0    Yes    PHP Session Support    Enabled    PHP Safe Mode    Disabled
AddDefaultCharset unset    Yes
Step 2
Please check the following files/folders are writeable before continuing...
wb/config.php    Writeable    wb/pages/    Writeable    wb/media/    Writeable    wb/templates/    Writeable
wb/modules/    Writeable    wb/languages/    Writeable    wb/temp/    Writeable
Step 3
erhalte ich folgende fehlermeldung:
Warning: fopen(../config.php) [function.fopen]: failed to open stream: Permission denied in C:\Inetpub\vhosts\pafjagd.de\httpdocs\install\save.php on line 317

Warning: Cannot modify header information - headers already sent by (output started at C:\Inetpub\vhosts\pafjagd.de\httpdocs\install\save.php:102) in C:\Inetpub\vhosts\pafjagd.de\httpdocs\install\save.php on line 81

was könnte falsch sein?
seafox