Running Windows XP Home SP2, using Outlook Express 6.

I have several identities set up and all are working OK, however, when
selecting:
File\Identities\Manage Identities, the 2 entries for
- Use this Identity when starting a program, and
- Use this identity when a program cannot ask you to choose an identity
are constantly set to the wrong identity.

Whenever I set them to the correct identity (Identity Ordinal 1) they always
revert to the previous identity (Identity Ordinal 2).

I have tried manually setting these in the registry to the correct identity
(Identity Ordinal 1) at
- HKCU\Identities Default User ID, and
- HKCU\Identities Start As
yet whenever I select File\Identities\Manage Identities, it resets the
values to the wrong identity (Identity Ordinal 2).

Is there some key that I can change to allow this change to stay
permanently, or could it be some other software (e.g. NIS, NAV, Spyware
Blaster) that is reverting these keys.

How can I fix this?