Oracle Unbreakable Enterprise Kernel and PeopleSoft

I have been building a PeopleSoft HCM 9.2 demo environment on PeopleTools 8.53.11 this past week. Since Oracle Linux is certified with PeopleSoft as well, I chose to use it for my OS. Everything went smooth, as I have done this kind of build many times. Got the app server and web server started, I was eager to get to the sign on page to try to login. However, the sign on page took a very long time (more than 30 minutes) to show up, with an error message: "CHECK APPSERVER LOGS. THE SITE BOOTED WITH INTERNAL DEFAULT SETTINGS, BECAUSE of: bea.jolt.ServiceException:bea.jolt.JoltRemoteService(.GETALL)call():Timeout\nbea.jolt.SessionException:Connection recv error\nbea.jolt.JoltException:[1]NwHddlr.recv():Timeout Error". Looked through all the app server logs and didn't find anything out of ordinary. Google showed no hits. Another strange thing was that the app server wouldn't shut down, even right after it's just brought up, it always hangs at the second process:

Shutting down server processes ...

Server Id = 250 Group Id = JREPGRP Machine = xxx.xxx.xxx: shutdown succeeded
Server Id = 200 Group Id = JSLGRP Machine = xxx.xxx.xxx:

 Opened a case with oracle support, not much help. Compared all the settings with our other working environments, not much difference. Really bothered me why it's not working. As a last effort, I switched back to boot with the RedHat Compatible Kernel, and issue disappeared! The problem kernel in my case is: 3.8.13-26.2.1.el6uek.x86_64. I would have never imaged that the unbreakable kernel would cause this issue, as I just built an Oracle 12c RAC with this kernel and my HCM 9.2 demo database has been running on this 12c RAC very well.