Cross referencing is defaulting back to last name sort

[joma]

I have cross referenced all entries in the address book so that I can look up
by name or company - two entries for each. I enter first by name then copy,
paste and change the list to display by name of company. Three times in the
past year this has defaulted back to last name sort with all the cross
referenced entries changed back. I now have two entries for Smith, John in
stead of one for Smith, John and one for ABC Printing. What could be
triggering this change. There are over a thousand entries and I have had to
reenter them manually before. The back-up is opening up with the same
problem, so I am thinking that there might be a setting somewhere in the
program that is being triggered when the program opens.

Thanks