Outlook could not find the requested contact. You don't have appropriate permission to perform this

My Windows XP downloads updates automatically for installation.

I'm not sure if it's a coincidence or not, but I'm noticing after a recent

update, that I'm having problems in Outlook (XP). Now, when I look up a

Contact in my address book, I get "Outlook could not find the requested

contact. You don't have appropriate permission to perform this operation."

Also, it seems like I'm having a problem opening email attachments.

Any ideas?

Thanks.