Want to center widget in right sidebar – causes merging of main/sidebar

I am using itheme2 and want to add some adsense ads in the right sidebar – simple.

But when I drag over a text widget to the sidebar and enter data – either adsense code or just plain text – it merges the center and right sidebar together. I tried using ad inject – same thing.

I also have an adsense search box in the lower sidebar (sidebar 2). Now if I keep it there, it comes out fine, but if I move it to sidebar one, I get the same merging effect.

I did, originally, put in a div code (in the widget) to center the text, and it worked fine for awhile, but then did not display the ads – only blank color, so I removed the widgets and started over. And now I get the merging effect when I try to add a widget.

The site is