Seam encodes URL parameters using UTF-8. Tomcat decodes URLs using ISO-8859-1. This leads to a number of problems. We need to find a way to make Seam and Tomcat use the same encodings.
A workaround is to set URIEncoding="UTF-8" on the HTTP connector in the tomcat server.xml.
This issue can be duplicated by entering non-standard characters into any field that will be copied to a page parameter. The search fields on any seam-gen application will produce the problem.