Group Policy Failed Error

we using windows server 2008 + sp2 enterprise edition 32-bit.  hardware dell r710 server.  group policy failed error @ regular intervals.  domain controller windows server 2008 + sp2 standard edition 64-bit.  adc there, loaded on vmware server.  forest level set windows server 2008 while loading, not have windows server 2003 dc's in lan.

 error details:
log name:      system
source:        microsoft-windows-grouppolicy
date:          1/20/2010 2:30:18 pm
event id:      1006
task category: none
level:         error
keywords:     
user:          system
computer:      stserver.qsidomain.net
description:
the processing of group policy failed. windows not authenticate active directory service on domain controller. (ldap bind function call failed). in details tab error code , description.
event xml:
<event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <system>
    <provider name="microsoft-windows-grouppolicy" guid="{aea1b4fa-97d1-45f2-a64c-4d69fffd92c9}" />
    <eventid>1006</eventid>
    <version>0</version>
    <level>2</level>
    <task>0</task>
    <opcode>1</opcode>
    <keywords>0x8000000000000000</keywords>
    <timecreated systemtime="2010-01-20t09:00:18.401z" />
    <eventrecordid>5845</eventrecordid>
    <correlation activityid="{c9253922-5785-4769-972d-051122703049}" />
    <execution processid="1040" threadid="5268" />
    <channel>system</channel>
    <computer>stserver.qsidomain.net</computer>
    <security userid="s-1-5-18" />
  </system>
  <eventdata>
    <data name="supportinfo1">1</data>
    <data name="supportinfo2">4934</data>
    <data name="processingmode">0</data>
    <data name="processingtimeinmilliseconds">4149</data>
    <data name="errorcode">52</data>
    <data name="errordescription">unavailable</data>
    <data name="dcname">
    </data>
  </eventdata>
</event>

Windows Server  >  Group Policy