"are no longer" - since when?

Some users are commenting that the addresses offered by auto-completion are now (since TB31) in an unexpected order, possibly because its search/filter criteria have changed. It used to look only at the start of names and addresses and now, I believe, looks for any substring, thus yielding a different ordering.

Over and above that, if Thunderbird isn't remembering settings between sessions, then I have to ask if you're using any tools such as CCleaner, which have a nasty habit of deleting Thunderbird configuration files. If so, set them to omit Thunderbird's profile

Zenos If I set the addresses into alphabetical order, then immediately either try to insert an address in a new email, or re-open the address book, the addresses are in no logical order.

Its a brand new laptop, I have run no cleaning tools yet, and thought I would try Thunderbird.

Very frustrated and disappointed so far

Did you do this: View > Show name as 'Last,First' View > Sort by > 'Name' and 'Ascending'

If no then what specific selections did you make?

As a test: Use the above settings and close the Address Book.

when you reopen the Address book, if the order seems wrong, before you do anything, please look at the : View > Show name - Is this still set 'Last,First' ? View > Sort by - Is this still set 'Name' and 'Ascending'?

Please say if they are still set but showing no logical order or what is now set for these two items?