Anchor and AutoSize Properties (on GroupBox, at least)

I had a weird problem earlier today involving the width of a GroupBox. I had dropped a GroupBox onto a panel. The panel was configured to automatically expand and contract as the size of the form is modified (using the Anchor property). I set the Anchor property on the GroupBox expecting it to be displayed in the same manner. But that was not to be

After a fair bit of fiddling around, I stumbled upon the problem. AutoSize. I had set AutoSize to true because I was dynamically adding controls that were to be displayed in the GroupBox. That setting, combined with the AutoSizeMode set to Grow and Shrink, let the control grow as I added more items.

What I didn't count on was that AutoSize also (appears) to control the horizontal size as well as the vertical. As a result, in order to get GroupBox to expand along with the size of the form, I had to turn AutoSize off and manually size the GroupBox as more items were added.

I am, however, open to other suggestion, should someone have one to offer.