Creating and opening a new pst in Outlook 2010 loses autocomplete

A customer was having problems with their pst file that a compact and a repair was not resolving.  So we thought we could open a new pst.  We did this and set it as default.  We found that the e-mails were still being sent from the old pst, so we removed the old pst.  As soon as we did that we lost the autocomplete.  The customer would like to view their old e-mails, so we would like to keep that pst open, but have the new one as default.

Is there any way to collect the old autocomplete file and bring it into the new pst.

There is just one profile, called Outlook - no new profile was created for the new pst file.

The customer is using Outlook 2010.