Five years ago (1997) we were at version 6.2A - so my guess is that 6.1 is not Y2K. If your client has run an integrity check with that version, it will discard all the sales data dated later that 1999 as having invalid dates.

If they want to use the sales analysis report that is provided, but limit to a single customer, then they should create an extract rule "Cusomter number is equal to xxxxxx" and edit the report to use the new rule. That should work.

They should also upgrade.