I had the same problem, you have to enable it int he manager.
Open up the realtek HD audio manager (shoudl be on the taskbar) on the right there is a panel that says analog, you will notice what looks like a folder. Open it. There check the option to disable the front audio port, I know it seems counter intuitive but it works.
As for overclocking, NEVER use applications to do it. The only time that is ever recommended is when you are going for an absolute WR and you are past the point of boot stable. Otherwise always use the BIOS. We have a guide here in the hardware section, its a little out of date but the lessons still apply.