Aero2: Main Site graphic keeps switching..

I went to the Aero2 control panel, and I changed the main site graphic to what I want it to be, but after a while, the graphic is reverting back to what it was before. What file contains the default graphic definition? Is it a skin-* file or a stylesheet? 

~/Themes/Aero2/Aero.config

Should be something like that anyhow. 

 Yep, got the right URL for the image in there. I believe I changed it in a stylesheet or in a file somewhere, overriding the main default graphic. I need to check there.

UPDATE: I found it. I copied the Aero2 over top of my default theme, and when I went to the default theme directory, the aero2.config had the wrong image url there. I changed the image url there, and then re-selected it from the control panel, and it was working right.