Problems with Active Directory sync

Hello,

i have a little problem with the active directory synchronisation.
The Astaro won't sync all Users of a specific group.
Here is the log entry of one unsynced user.

2011:07:08-21:06:54 gw1-1 user_prefetch[11202]: # 34 Creating user user.abc
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: Failed to set object
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: >=========================================================================
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: $VAR1 = [
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'ALREADY_IN_USE_OBJECT',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: {
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objclass' => 'aaa',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'attrs' => [
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'value',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objname'
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: ],
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objname' => 'user.abc',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'value' => 'userabc@domain.de',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objattr' => 'email_primary',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'name' => 'Die E-Mail-Adresse \'userabc@domain.de\' wird bereits durch das \'user.abc\'-Attribut im Benutzer-Objekt \'\' benutzt.',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'msgtype' => 'ALREADY_IN_USE_OBJECT',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'never_hide' => 0,
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'Oattrs' => [
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objclass',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objtype'
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: ],
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'format' => '%_e \'%s\' wird bereits durch das \'%s\'-Attribut im %_O-Objekt \'%s\' benutzt.',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'objtype' => 'user',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'user' => 'Object:aaa->user->email_primary:REF_xxIHFejSae',
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'fatal' => 1,
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: 'class' => 'email_user'
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: }
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: ];
2011:07:08-21:06:55 gw1-1 user_prefetch[11202]: