Disabled check boxes for exclusions on the Import Patch Data for Windows (PMImport) > Vendors and Software section, enabled the setting 'Delete previously downloaded data for vendors, software and languages that are now excluded' and executed the process as seen here:
Found the process fails with exception errors in log viewer.
Exception occured while executing task c27dbb50-6ddf-4125-87c1-d8f5b588491d. Unable to cast object of type 'Altiris.SoftwareManagement.Resources.SoftwareUpdateResource' to type 'Altiris.PatchManagementCore.Resources.PatchSoftwareUpdateResource'.
Software Management associations, or other resources, have become associated to the Patch Software Release that is being disabled and the process is unable to clean-up the improper associations.
Work through the following to resolve this in the SMP Console:
This issue is resolved with 8.0 HF1 DOC9271