All of a sudden, my Google Chrome (version 22.0.1229.79 m) started appending the same search term twice whenever I type in the address bar. I was looking for a way to fix it for long time and got it today.  I believe it is because of the search engine settings (honestly, I don’t know what went wrong). To fix it

1. Right click anywhere on the address bar in Google Chrome
2. Select “Edit search engines…”
3. That might show something similar to this
   
4. If Google is the default search engine, move the cursor over any other search engine and click on “Make Default”
5. Move the cursor over the Google’s entry and you will find a cross mark at the right end. A click on it would remove the entry. Just click on it.
6. Now in the Other search engines section, type Google in the first two boxes and then type http://www.google.com/search?hl=en&q=%s in the third box and press Enter.
7. The Google entry would have got added to the default search settings. Make it as the default search engine.

Enjoy Google’s search service :)