First, this version is very stable. Compare to previous version, I almost convince this OS is bug free. My UDOO use this version run 1 week without any problem. Yesterday, I saw things broken. To reproduce this issue, 1.install tomcat7 2.start remote client 3.open browser , browse yahoo news 4. put it there without moving for 4 days The console in demsg /var/log tail -f dmesg shows I guess this is some driver issue... This board is interesting, I learn lots of debug technique from it... Code: [701263.360773] Alignment trap: not handling instruction e1903f9f at [<805c037c>] [701263.360784] ------------[ cut here ]------------ [701263.360797] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [701263.360821] WARNING: at drivers/tty/vt/vt.c:3795 do_unblank_screen+0x104/0x194() [701263.360829] pgd = b9894000 [701263.360834] Modules linked in: [701263.360840]  *pgd=49927831 vivante drm [701263.360857] Unable to handle kernel paging request at virtual address 5d2cc74a [701263.360885] [<800475d4>] (unwind_backtrace+0x0/0xfc) from [<800755e8>] (warn_slowpath_common+0x4c/0x64) [701263.360894] pgd = b9894000 [701263.360907] [<800755e8>] (warn_slowpath_common+0x4c/0x64) from [<8007561c>] (warn_slowpath_null+0x1c/0x24) [701263.360916] [5d2cc74a] *pgd=b9f11bc000000000[<8007561c>] (warn_slowpath_null+0x1c/0x24) from [<802dcfdc>] (do_unblank_screen+0x104/0x194) [701263.360933] [701263.360953] [<802dcfdc>] (do_unblank_screen+0x104/0x194) from [<802816c8>] (bust_spinlocks+0x24/0x4c) [701263.360984] [<802816c8>] (bust_spinlocks+0x24/0x4c) from [<805bdaf8>] (__schedule+0x280/0x690) [701263.360996] ---[ end trace 922876d73f783336 ]--- [701263.361009] Unable to handle kernel NULL pointer dereference at virtual address 00000014 [701263.361017] pgd = 80004000 [701263.361024]  *pgd=bfec9c5000000000 [701263.480294] Unhandled fault: alignment exception (0x001) at 0x00000503 After this, system hang there. Console not moving, remote ssh broken. No way to ssh get in. System dead.