[balinor]

You guys are talking about two different versions here. The 4.0 branch did not have a check box for 'same as billing', so if that is present in your 4.0.x cart, it is an add on of some sort.

For the 4.1 branch, was this when you used Autofill per chance?

And mawalshy, if you could please update your forum signature with your X-Cart version per the forum guidelines that would be great. Thanks!