This is something I discovered recently, that I think might be useful to someone.

If your search bar and log off buttons are not positioned right on the start menu, this might work for you.

I've learned that the search bar and buttons are directly connected to the width of your Programs List and Places List.
In the picture below, you can see the left startmenu has the same size for both the Programs List and the Places list. The right edge of the search bar,  and the left edge of the buttons are "stuck" to the center of the start menu.
On the right startmenu, I've adjusted the sizes of the parts and it automatically positioned the search bar and buttons to where they should be.

I did not change any graphics! Using SKS6....All I did was go into the "Extras" tab on the Programs List and increase the number for the Width Of Part (Vista), then I went into the "Extras" tab for the Places List and decreased the Width Of Part(Vista) by the same ammount.

This may or may not work for you, depending on how complex your start menu is ...but on mine, because it's so "simple", it worked like a dream.