Hello Kevin,
I tried all the steps described in the link you provided. Thanks. Nothing helped. Meanwhile I got the board exchanged. But I'm having problems with the new board again. I would question my experience if I had not built the same system before.
The problems I have with the new board are different though. It boots and after running for a while it turns off suddenly. This may happen several minutes or 30 seconds after booting. It happens while in the OS (BSD) or while in the BIOS menu.
As I said on my first post, I tested the very memory module and hard disk I use in the second system in my first system (which runs fine since several months).
I want to build a PFSense firewall. I googled around and a lot of people have used this motherboard for the same system. I'm really flabbergasted why I'm having so much problems with this.
Thanks for any ideas you might have