WordPress Plugin Appends ugly url string to index

A custom background plugin has started to cause certain browsers (FF开发者_JAVA技巧, IE8,9, Safari) to reveal an appended url string when viewing the index page: http://dearearth.net - this mostly shows when not visiting the site directly, but rather when going through, for example, google - http://www.google.com/search?sourceid=chrome&ie=UTF-8&q=dear+earth.

This persists in IE 9 even after refresh or page reload, but does not on the other browsers.

Screenshot: http://i55.tinypic.com/2nv9fh3.jpg

I have the following custom permalink structure enabled:/%category%/%postname%/

Thanks for any input!

You could try resetting your permalinks, then setting them again, this often clears up permalink issues.

edit

I think you should drop the plugin. Use the body_class() method to identify different pages that use the same template, and attach different backgrounds to different pages in CSS.