"An unexpected error has occurred" when sending from distribution lists

[Tom2]

I have set up a new computer, installed Outlook 2002 on it
and migrated my files to it from the previous computer.
Now whenever I attempt to send an email addressed via one
of my distribution lists, I get an error message (An
unexpected error has occurred). I also see two Contacts
folders in the Add Address List in the Tools/options in
the address book.

I did change the location of the Outlook pst files, did I
confuse something or ?

Any ideas? Nothing in the Knowledge base helped

Thanks.