Customer was running PA_Agent_Installer on Unix/HP-UX and it seemed to hang (customer waited over 30 minutes).
The login account did not have sufficient access rights.
Solution 26439 suggests "chmod 777 /tmp".
Since the Oracle software owner (usually the "oracle" account) is more of a known quantity, and the customer had ready access to the "oracle" account, they were advised to login as this user and try the install again. If there were any problems with the "oracle" login, they were advised to follow the "chmod 777 /tmp" suggestion (solution 26439) to make sure "oracle" had proper access to the /tmp directory.