Toolbar will always slide to the right side on start up

[asm23]

How can I demonstrate this problem. I just snap the screen.
I'm using window xp en. Lyx 1.6RC3.

This is the toolbar before I close:
http://zyh23.diinoweb.com/files/openPic/good1.jpg
And ,this is the toolbar when I restart Lyx: the toolbars will slide to 
the right corner.
http://zyh23.diinoweb.com/files/openPic/error.jpg

I test it in Big icons, normal icons and small icons mode, and they all 
have this problem.