Yes, but keep in mind that if you are entering an old report (for example, say it's 3rd Quarter 2009 and you want to fill in your 1st and 2nd Qtr 2009 reports for historical purposes), that most of the auto-pop routines won't be able to run because they will be looking for month-end files that no longer are stored on the system.  But that's okay - the auto-pops will run if they can, but if they can't you'll just see a blank field you'll have to fill in manually.

Also remember that any Account Codes that were added by the NCUA since that quarter's format will appear, even though they might not have been relevant at the time that report was actually filed.  Just ignore those fields.  (Likewise, Account Codes that have subsequently been deleted, which happens only rarely, will no longer be available when producing old reports.)