After installing ubuntu 13.04 on my new Samsung Series 9 NP900X, alongside the pre-installed Windows 8, when booting it goes directly into Windows 9. I tried fixing the problem as descrbied here: https://help.ubuntu.com/community/Boot-Repair
But, the problem persists. Here is the error log file generated by boot-repair: http://paste.ubuntu.com/6325540/
Any suggestions on what should I try next?