I am logged onto my PC with a domain account that is in the local Administrator group for the PC. This does seem to be a registry permission issue. I've deleted the entries that Shawn mentioned, and when I run regsvr32 it still fails with the same error, however it does recreate the entries. I changed my permissions to 'Full Control', however it is reset on this Key after running RegSvr32 back to 'Special' (Full Control on this Key only - but on each Key in the section). I hope this is as clear as mud.

Thanks again for your help.
Ben