UPDATE
I just got home and did some testing. I am not sure what the problem was as swapping between the default test images and the images I had in place didn't make a difference and looking at the CSS there should not have been an issue. Anyway, when I removed the old product table and replaced it with the default one it seemed fine. When I replaced it again it was messed up.
What I ended up doing was changing the featured product tot another item and it fixed it. Even reverting back to the old featured item seems to be okay now. I'm guessing that the data needed to be refreshed??
This may never happen to anyone else but if so, there you go...