drush error while updating modules (Failed to backup project directory)

Hi,

i have drush up and running but i get an error while updating modules of one site. The problem must be that it's the only site which is not created by aegir but imported manually. So that's why there is a symlink from default -> myImportedSite.nl

here is drush -d updatecode

Including non-version specific file : [notice]
/var/spool/www/user/aegir/drush/commands/pm/package_handler/wget.inc
[16.159 sec]
Including non-version specific file : [notice]
/var/spool/www/user/aegir/drush/commands/pm/version_control/svn.inc
[16.16 sec]
Code updates will be made to the following projects:
Content Construction Kit (CCK) [cck-6.x-2.4], Organic groups [og-6.x-2.0-rc3]

Note: Updated modules can potentially break your site. It's not recommended to update production sites without prior testing.
Note: A backup of your package will be stored to backups directory if it is not managed by a supported version control system.
Note: If you have made any modifications to any file that belongs to one of these projects, you will have to migrate those modifications after updating.
Do you really want to continue? (y/n): y
Starting to update Content Construction Kit (CCK) code ... [21.718 [notice]
sec]
Calling mkdir(/var/spool/www/user/aegir/drupal-6.12/backup, 511)
Calling mkdir(/var/spool/www/user/aegir/drupal-6.12/backup/modules, 511)
Calling mkdir(/var/spool/www/user/aegir/drupal-6.12/backup/modules/20090630140747, 511)
Calling rename(/var/spool/www/user/aegir/drupal-6.12/sites/myImportedSite.nl/modules/cck, /var/spool/www/user/aegir/drupal-6.12/backup/modules/20090630140747/cck)
drush: Failed to backup project directory /var/spool/www/user/aegir/drupal-6.12/sites/myImportedSite.nl/modules/cck to /var/spool/www/user/aegir/drupal-6.12/backup/modules/20090630140747/cck

regards Volkan