Events generated by the modification of GPO Precendence

Hi,

I've been tasked to write a powershell script which generates report of GPO auditing.
It works great for all modifications except the change of GPO Precedence.

I thought modifying GPO Precedence will generated 2 events, one for the old value deleted and one for the new value added, like other modifications.
When I try in my lab I was suprised to see 8 events generated.

For example, here are the value of the 8 events generated (most recent in first):

Value:[LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Added

Value:[LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Deleted

Value:[LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Added

Value:[LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Deleted

Value:[LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Added

Value:[LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Deleted

Value:[LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Added

Value:[LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Deleted

I thought it will be directly that :

Value:[LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Added

Value:[LDAP://cn={2F8F9B73-9AE6-4106-A625-898F14A6E293},cn=policies,cn=system,DC=audit,DC=posh;0][LDAP://cn={6289B536-D1E0-4F07-9FC8-B583A7EC3DAF},cn=policies,cn=system,DC=audit,DC=posh;0]
Type:Value Deleted

Does anyone know why changing the GPO Precedence generates 8 5136 events ?

Thanks,