Just an update that this all worked perfectly, and the script is now perfect. Thanks, everyone, for your oustanding help!

So how'd you do it? Using a model shaped to the pudle, with 8 skins?

I took the model idea, but changed it slightly. I created a flat round model and attached no skin. I then imported this into my level and positioned it over the TGA, set it to unlit and invisible, and used that for collision detection of the ball. That way, I was able to keep all of the water puddles I had as TGAs without having to remake each one. The end result is completely the same, and you can't tell that the invisible models are there.

Good Idea! Glad it worked out for you...

Congratulations!

Could you post a screenshot or two, I'd like to see what it looks like.

Two images for you, although it might be kind of hard to see the puddles without actually playing the level:

You're right i haven't found 'em
BTW nice level