WSUS 3.0 some computers not updated

Few machines are not getting updated, getting this on the log:
###########  AU: Uninitializing Automatic Updates  ###########
2008-05-12      13:12:29:575      1052      7f8      AU      ###########  AU: Initializing Automatic Updates  ###########
2008-05-12      13:12:29:575      1052      7f8      AU      AU setting next detection timeout to 2008-05-12 17:12:29
2008-05-12      13:12:30:231      1052      7f8      Agent      WARNING: GetServiceList failed with error 0x80004002.
2008-05-12      13:12:30:231      1052      7f8      AU      WARNING: QueryRegisteredProvider failed with error 0x80004002
2008-05-12      13:12:30:231      1052      7f8      AU        # WSUS server: http://shqitosus01
2008-05-12      13:12:30:231      1052      7f8      AU        # Detection frequency: 1
2008-05-12      13:12:30:231      1052      7f8      AU        # Approval type: Scheduled (Policy)
2008-05-12      13:12:30:231      1052      7f8      AU        # Scheduled install day/time: Every day at 3:00
2008-05-12      13:12:30:231      1052      7f8      AU        # Auto-install minor updates: Yes (User preference)
2008-05-12      13:12:30:810      1052      7f8      AU      FATAL: Failed to get session from datastore, error = 0x80004002
2008-05-12      13:12:30:810      1052      7f8      AU      FATAL: Failed to Unserialize from data store, error = 0x80004002
2008-05-12      13:12:30:810      1052      7f8      AU        # WARNING: Exit code = 0x80004002
2008-05-12      13:12:30:810      1052      7f8      AU      ###########  AU: Uninitializing Automatic Updates  ###########
2008-05-12      13:12:30:810      1052      7f8      AU      WARNING: InitAUComponents Failed, will restart AU in 30 mins, error = 0x80004002
2008-05-12      13:12:30:810      1052      7f8      AU      AU Restart required....Start Free Trial