We fixed the issue, it was motherboard related.

1) Update the bios
http://www.biostar.com.tw/app/en/mb/introduction.php?S_ID=865#download


2) Follow this guide from biostar:
http://www.biostar.com.tw/app/en/support/faq_content.php?S_ID=768

Super stable and mining for a week now.

Cheers!