problem with menu

Hi – First off thanks for the great plugin!
There is a problem with the search results page and function wp_nav_menu.
I saw some of the comments already written that they have identified this problem …
When Im in search-results-page and plug in is on – the menu goes wrong and does not work well and just shows all the pages in site …
If I turn off the plugin – menu suddenly returns to normal – so I’m convinced there is a problem with plugin and wp_nav_menu ().
This search results page –
http://174.137.187.89/~tnmlimit/?search-class=DB_CustomSearch_Widget-db_customsearch_widget&widget_number=preset-default&country-0=project&cs-country-1=Ecuador&cs-services-2=&cs-markets-3=&search=Search
Note that the menu does not work well and just gives all the pages on …
this is standard page on the site:
http://174.137.187.89/~tnmlimit/business/projects/
Note that here evrything is all right …
I’d be delighted if you could help me with this.
Thank you.

http://ww.wp.xz.cn/plugins/wp-custom-fields-search/