Random USB Bootable stick detection failure

Hi,

I am having a desktop with Intel DH77EB motherboard. I have created a bootable XUbuntu stick and the BIOS detects it. To test whether in every reboot it is detected, I have kept a reboot test in this system for every 12 minutes. After about 50 to 60 reboots the BIOS fails to detect the bootable USB stick. If I switch off and on the system the USB stick is again detected. We are building production systems using this Motherboard. So we expect that this kind of rigorous tests should pass.

Please update if you have any suggestions.

I have already disabled fast boot. I am using SanDisk Cruzer 16GB stick as bootable device.

Thanks in advance,

Subbarao