Gaspar Bakos wrote:
I am trying to figure our what is causing it: hardware error? If yes, harddrive or memory?
You could try running memtest86 - install it (yum install memtest86), reboot and select memtest from Grub's menu - this should spot memory issues, and I believe some motherboard issues. Here's the website with more info:
http://www.memtest86.com/ HTH.