Thanks Dani, that seems to have fixed it. I have another problem which I hope you can give me a steer on. sportsman.php pulls all available records from a db table "sportsman", and when you click on one it should select any listings for that individual and display them on the next page (sportsmanResults.php) - so if there were two listings with the same ID (ie two for David Beckham) it would show both of these as a thumbnail image. You then click on whichever you want to view and it gives more detail on the final page - sportsmanDetails.php - pulled from the db table "sporting".
What's happening though is that although there are 15 listings in "sportsman" and 3 in "sporting", the results page shows all 3 listings from "sporting" rather than whichever one matches the ID assigned to the sportsman.
I've no idea why this isn't working - again, the live site will show what's happening, but I've attached the 3 pages as a zip file.