And the moral of the story is ..
Thanks to Plip (have you got a blog??) a security hole was fixed in one of my sites today. It's that old problem of writing something quick and temporary and then leaving it there forever. I am afraid I am a lazy programmer when it comes to my own stuff and I tend to do these "tactical quick-wins" as a colleague likes to call them ("hacks" is probably more accurate) more often than I would like to admit.
The moral is write correctly first time even if it means delivering late.
Any benefit of having something up early would have been way offset had someone a hell of a lot less ethical and sharp as Phil had discovered the schoolboy error I had made. I've learnt my lesson the easy way and I am very grateful!