I have 2 forums affected and on one the site title and cookie domain fields were blanked so I redid them and presto it seems fine.
There are no new or blank forums I have found, the poker forum is still screwed and the admin title and cookie fields have not been altered but that forum is still redirecting.
I have found in the view source this:
It is confusing it is not the same method for both boards that has been used!