[Plugin: Easy Adsenser] Google Custom Search

Hi, I’m trying to setup widget with “Google custom search”. When I enter some text to search I get this error:
The requested URL /cse?cx=partner-pub-4678430184250089%3A6qwwsl-alx9&ie=ISO-8859-1&q=aaaaaaaa&sa=Search&siteurl=mysite_whatever.com%2F was not found on this server.

My Adsense adverts work fine, the only problem is with the search – should I customise the code for it? How? Thanks!