It looks as though you have misunderstood what I'm trying to say Colin.
If you can imagine a forum page which has been created using software, or a computer programme if you like, the dimensions of the page, or how many posts it will hold before the next page is begun, are decided by the software.
The software for creating forum pages was different when the Permanent Caravanning topic started in 2007.
When the forum upgrade took place last year different software was used to the original and one thing that has happened is the the 'new' pages created by this later software are of a different size to the old forum pages.
Normally this doesn't matter because topics which come and go now fit into the forum pages created by the new software.
This old topic uses less space on the forum pages in the old version so two or three of the new sized pages are left over.
Imagine having an exercise book with pages that hold 100 words, if you wrote 1000 words you would use ten pages.
If you swapped the exercise book for one with bigger pages which held, say, 120 words at some point during the writing you wouldn't use ten pages meaning you'd probably have some pages left over.
If somebody adds a new post to the Permanent Caravanning thread it just goes on the end of what has already been written and all that you have to do to read the latest post is to click 'previous' from the blank surplus pages until you come to a page which contains text. The last posting will be the last one on that page.
If someone adds a further post it is automatically added after the previous one and the 'spare' blank pages should be ignored.
Nothing can be done now about the extra pages because the entire topic would disappear.