security log events

Is it normal to have security log on our Windows 2003 server (acting as a
domain controller) flooded with the following events? Every 2 to 4 minutes I
get about 15 events.
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Event Type: Success Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 576
Date: 18.10.2005
Time: 5:00:25
User: NT AUTHORITY\SYSTEM
Computer: SERVER
Description:
Special privileges assigned to new logon:
User Name: SERVER$
Domain: MYDOMAIN
Logon ID: (0x0,0xE6B96F)
Privileges: SeSecurityPrivilege
SeBackupPrivilege
SeRestorePrivilege
SeTakeOwnershipPrivilege
SeDebugPrivilege
SeSystemEnvironmentPrivilege
SeLoadDriverPrivilege
SeImpersonatePrivilege
SeEnableDelegationPrivilege

For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
-------------------------------------------
Event Type: Success Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 540
Date: 18.10.2005
Time: 5:00:25
User: NT AUTHORITY\SYSTEM
Computer: SERVER
Description:
Successful Network Logon:
User Name: SERVER$
Domain: MYDOMAIN
Logon ID: (0x0,0xE6B96F)
Logon Type: 3
Logon Process: Kerberos
Authentication Package: Kerberos
Workstation Name:
Logon GUID: {67611579-f981-5e9d-8f0e-5624639cab45}
Caller User Name: -
Caller Domain: -
Caller Logon ID: -
Caller Process ID: -
Transited Services: -
Source Network Address: 192.168.1.251
Source Port: 0


For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
-------------------------------------------
Event Type: Success Audit
Event Source: Security
Event Category: Logon/Logoff
Event ID: 538
Date: 18.10.2005
Time: 5:00:36
User: NT AUTHORITY\SYSTEM
Computer: SERVER
Description:
User Logoff:
User Name: SERVER$
Domain: MYDOMAIN
Logon ID: (0x0,0xE6B96F)
Logon Type: 3


For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
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