Followed process detailed on KM: HOWTO79488; however, the targeted custom filter for the 'Windows Patch Remediation Settings' policy is being removed.
Found the clean up process clears the custom filter from the policy if it is not 'accessed' within 7 days. This is to prevent target membership bloating within the Symantec_CMDB database.
However the targets for the Windows Patch Remediation Settings policy are stored in the "State" column of the the policy, in the ITEM table; as a result tracking its usage does not seem to occur.
Advisory: this Target will be cleared if anything other than the default: 'Windows Computers with Software Update Plug-in Installed Target'
This issue is resolved in ITMS 7.5.
ITMS & Patch Management 7.1 SP1, SP2 & MP1.x