Forum code error

[pweller]

If you look at some threads ('A message to fergie from us' being one) you will notice they have a 'ghost' last page that doesn't exist.

[RTGAdmin]

What is your number of posts per page set to?

You can check this here

[pweller]

20 posts per page, it's been set to that for years but this 'ghost page' problem only started a couple of month ago.
Tried ie, google chrome and firefox in case it was browser specific but it's the same on all three.