Office 2003 - Windows XP

Last month I took a long holiday vacation - in anticipation of an extended
time away from my home computer, I copied my Outlook data file (.pst) so that
I could continue to use all my contacts, calendar, mail, etc. in my father's
computer.  It was easy enough to create a new profile and direct it to my
data file.  Two weeks later, I copied my data file from my father's computer
and replaced the one in my own computer once I got back home.

The problem I noticed is this: While composing a new email message I click
on the "To:" tab to select email recipients.  The new contacts that I added
since I've been back do not show up in the list.  Then I'll click on Contacts
and scroll down to the same contact and find it right there.

My new contacts will not show up as mail recipients.  I have to select them
from Contacts individually and send "New Email to Contact".

Please assist.