Back again taking Joshpet's advice to post this query here as well.
With Classic I could go into my Admin and delete all the old posts very easily in chronological order.
The older threads which hadn't been posted to in some time appeared one after another at the bottom of the list and it was easy as pie to go in and delete.
Threads on the other hand is terrible
The threads started the longest time ago do indeed appear at the bottom of the prunage list regardless of whether they've been posted to recently??
"Help?"