Upon further testing here are my conclusions ..
I did a fresh installation of ClearOS 5.2 SP1 and configured the PPPoE dialer. Everything was fine until it hit the 8 minute mark then the link got disconnected. I then proceeded to run the system update on the installation and the connection did not drop at all beyond the 8 minute mark.
Can't recall what system updates was there, but I'm pretty sure that one of it stopped the disconnections.