Nick the problem is the first error line you provide:
02-16-2007,09:16:28 : ERROR: Failed to register/unregister D:\Program Files\Symantec\BACKUP~1\NT\pvcalendar.ocx with regsvr32.
This could be due a number of variables one of which is a problem with WMI, review the technote below and use the steps provide and try installation again.
Document ID: 285328
http://support.veritas.com/docs/285328
It's also possible there could be a problem with the 8 dot 3 name creation; the steps in the technote below should help resolve that possibility.
Document ID: 285472
http://support.veritas.com/docs/285472
