Blank page error when using custom taxonomy term in search query

Hey,
I've used CustomPress to set up custom post types and custom taxonomies. I recently noticed that when I search for one of the terms I used in the custom taxonomy, I get a blank page error. Other terms work just fine. For example, I can search for "localization" but not "accounting".

See: http://probizservices.com/business-services-catalog/

The search bar on the left is a site-wide search and the one in the page just searches custom post types, but I get the error with both.