Hi Takashi, First I appreciate your help on this item. I have been on 3.17.6-1.g12b7bf1-desktop five days, booting as a test several times a day, without a single boot issue. So it does appear there is some kind of regression from 3.17.6-1.g12b7bf1-desktop to 3.18.6-1.1 (which does have this boot issue). Can I do something else to help resolve? Perhaps installing a different distro with kernel 3.18 or higher on a USB? Or ask on the factory mailing list if others have similar issue? My hardware is about 4 years old, both the motherboard and CPU came out new then, so I'd wild guess that hardware of the same type 2-4 years old would have the same issue, so it seems worth following up for others on similar hardware. Thanks Milan