I did see this thread about setting up attributes:

http://www.zen-cart.com/forum/showthread.php?t=4810

But I'm having a different problem.

I've set up two different attributes for a product: feature1 and feature2 are the two options I offer.

Yet, when you go to purchase the item, BOTH of these attributes are automatically checked!
I have the "required" button checked off for both of them. I have also tried UNchecking the required button for both, and checking it for one and not the other.

And.....when you try to click a radio button, it will not un-check either of these options.

WHAT AM I DOING WRONG?