Unattended NetBackup 10.1 Client upgrade

I'm trying to upgrade NetBackup clients using the Linux-based client install. I've provided an answer file in /tmp/NBInstallAnswer.conf with ACCEPT_EULA, PROCEED_WITH_INSTALL, and INCLUDE_JAVA_GUI_AND_JRE, but the script keeps prompting me to answer "Do you want to install the NetBackup client software for this client? [y,n] (y)". How do I get it to upgrade without any prompts?