Hey,

Thank you very much. The Multiple Category Selection Widget is great.
If anyone knows a similar plugin, please let me know.

Big feature rocks!

all plugins work with default theme, because the developers test with it. It probably shows a custom not found template. I will add it to the plugin list that I will try to make compatible with the theme

I used the Multiple Category Selection Widget in Big Feature:

http://wordpress.org/extend/plugins/multiple-category-selection-widget/

This plugin gives you the ability to provide your users with a widget full of dropdowns based upon parent categories and their sub-categories. Multiple subcategories spanning multiple parent categories (though multiple categories inside a single parent cannot be chosen) are chosen and intelligently filter your posts. Users should now be able to search for your post under all those categories!

However, if I search with this widget and there are no results found, the whole sidebar moves to the leftside of the page.
If i change the template to the WordPress Default 1.6 there is no problem.
I tried to change the archive.php but that didn't work out.

Please help me out.
Thank you.