Agent truncates filtered HTTP POST body

Steps to reproduce:
1. Install Apache webagent 4 in CDSSO configuration
2. Install Tomcat and setup FileUpload according to: http://www.codejava.net/java-ee/servlet/apache-commons-fileupload-example-with-servlet-and-jsp
3. Install mod_jk and add /uploadFile/* in JkMount configuration
4. Add /uploadFile/* resource to not-enforced list
5. Open upload.jsp, authenticate, and pick any file greater than 4K in size for upload.

Observed result: browser displays either empty screen or "the stream ended unexpectedly" error message.

Expected result: file is uploaded successfully.