As to the original problem, the best thing I can come up with is for you to increase the max http header size in the tomcat connector config.

<Connector port="8080" maxHttpHeaderSize="32000"
              maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
              enableLookups="false" redirectPort="8443" acceptCount="100"
              connectionTimeout="20000" disableUploadTimeout="true" />

i.e. increasing the maxHttpHeaderSize. By default it's 8k I believe.

http://tomcat.apache.org/tomcat-5.5-doc/config/http.html