Outstanding! I think they call this "collaboration".
Supposedly, the default of VALUE is the content of the OPTION, which must be why it wasn't coded your way in the first place. It must be that some browsers (IE?) don't honor this default. I did my testing with Mozilla, so I didn't see the problem. I'm sort of glad that I didn't; it might have discouraged me from implementing my mod.
I tried without your fix on IE, and it gave me the same problem you saw. So I applied your fix, and all is well now.
By the way, you said "register_billing_info.tpl" and "register_shipping_info.tpl" - I think you meant "register_billing_address.tpl" and "register_shipping_address.tpl" . I knew what you meant, but conceivably someone out there might not.
Griff