Please bump this thread up in prioirty.  This is causing me to have to reboot my machine at least once per day, and I've discovered can trigger very suprising and unpleasant things to happen.

So when atkbd goes nuts, it starts generating random keypresses.  I've seen these keypresses appear in whatever window or terminal happens to have focus at the time, and they can include ANY key events, from alpha-numeric to F-Keys to, as I've discovered today, SysRq combos.

Today, my computer appeared to crash.  I had opened a bug for that before: bug #984273 where the syslog was suddenly flooded with Emergency Thaw messages, triggering a buffer overflow on klogd, causing malformed messages written to the log, memory filling up until there was none left and eventually, system crash.

This happened again this morning and I finally know what's triggering it.  It's THIS bug, with the atkbd problem I've been experiencing since I installed Precise on this machine. 

Here are some excerpts:
The first instance happened at 0854 this morning: (The atkbd messages have been appearing longer, but the first time it hit SysRq was at 0854).

Jun 20 08:54:04 klaatu kernel: [85700.498471] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:04 klaatu kernel: [85700.498480] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:04 klaatu kernel: [85700.543991] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:04 klaatu kernel: [85700.544000] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:04 klaatu kernel: [85700.545264] SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) thaw-filesystems(J) saK show-backtrace-all-active-cpus(L) show-memory-usage(M) nice-all-RT-tasks(N) powerOff show-registers(P) show-all-timers(Q) unRaw Sync show-task-states(T) Unmount show-blocked-tasks(W) dump-ftrace-buffer(Z) 
Jun 20 08:54:04 klaatu kernel: [85700.548084] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:04 klaatu kernel: [85700.548093] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:04 klaatu kernel: [85700.645263] atkbd serio2: Unknown key pressed (raw set 2, code 0x18 on isa0060/serio2).
Jun 20 08:54:04 klaatu kernel: [85700.645272] atkbd serio2: Use 'setkeycodes 18 <keycode>' to make it known.

Next, it hit the SysRq combo to change log level:

Jun 20 08:54:06 klaatu kernel: [85702.601963] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:06 klaatu kernel: [85702.601971] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:06 klaatu kernel: [85702.678295] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:06 klaatu kernel: [85702.678303] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:06 klaatu kernel: [85702.679470] SysRq : Changing Loglevel
Jun 20 08:54:06 klaatu kernel: [85702.679479] Loglevel set to 0
Jun 20 08:54:06 klaatu kernel: [85702.681515] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:06 klaatu kernel: [85702.681522] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:06 klaatu kernel: [85702.826266] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:06 klaatu kernel: [85702.826274] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.

Then SysRq alone again:
Jun 20 08:54:06 klaatu kernel: [85702.950885] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:06 klaatu kernel: [85702.950894] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:06 klaatu kernel: [85702.952214] SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) thaw-filesystems(J) saK show-backtrace-all-active-cpus(L) show-memory-usage(M) nice-all-RT-tasks(N) powerOff show-registers(P) show-all-timers(Q) unRaw Sync show-task-states(T) Unmount show-blocked-tasks(W) dump-ftrace-buffer(Z) 
Jun 20 08:54:06 klaatu kernel: [85702.955870] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:06 klaatu kernel: [85702.955878] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.

A second later it hits another SysRq combo:
Jun 20 08:54:07 klaatu kernel: [85703.516958] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:07 klaatu kernel: [85703.516964] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:07 klaatu kernel: [85703.533880] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:07 klaatu kernel: [85703.533889] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:07 klaatu kernel: [85703.535377] SysRq : Show Blocked State
Jun 20 08:54:07 klaatu kernel: [85703.535385]   task                        PC stack   pid father
Jun 20 08:54:07 klaatu kernel: [85703.535612] Sched Debug Version: v0.10, 3.2.0-25-generic #40-Ubuntu
Jun 20 08:54:07 klaatu kernel: [85703.535617] ktime                                   : 85788353.151918
Jun 20 08:54:07 klaatu kernel: [85703.535622] sched_clk                               : 85703535.609556
Jun 20 08:54:07 klaatu kernel: [85703.535626] cpu_clk                                 : 85703535.609650
Jun 20 08:54:07 klaatu kernel: [85703.535630] jiffies                                 : 4316339384
Jun 20 08:54:07 klaatu kernel: [85703.535634] sched_clock_stable                      : 1
Jun 20 08:54:07 klaatu kernel: [85703.535637] 
Jun 20 08:54:07 klaatu kernel: [85703.535639] sysctl_sched
Jun 20 08:54:07 klaatu kernel: [85703.535642]   .sysctl_sched_latency                    : 24.000000
Jun 20 08:54:07 klaatu kernel: [85703.535647]   .sysctl_sched_min_granularity            : 3.000000
Jun 20 08:54:07 klaatu kernel: [85703.535651]   .sysctl_sched_wakeup_granularity         : 4.000000
Jun 20 08:54:07 klaatu kernel: [85703.535655]   .sysctl_sched_child_runs_first           : 0
Jun 20 08:54:07 klaatu kernel: [85703.535658]   .sysctl_sched_features                   : 24119
Jun 20 08:54:07 klaatu kernel: [85703.535663]   .sysctl_sched_tunable_scaling            : 1 (logaritmic)
Jun 20 08:54:07 klaatu kernel: [85703.535668] 
Jun 20 08:54:07 klaatu kernel: [85703.535670] cpu#0, 1595.815 MHz
Jun 20 08:54:07 klaatu kernel: [85703.535673]   .nr_running                    : 0
Jun 20 08:54:07 klaatu kernel: [85703.535677]   .load                          : 0
Jun 20 08:54:07 klaatu kernel: [85703.535680]   .nr_switches                   : 76630310
Jun 20 08:54:07 klaatu kernel: [85703.535684]   .nr_load_updates               : 6773816
Jun 20 08:54:07 klaatu kernel: [85703.535688]   .nr_uninterruptible            : -44775
Jun 20 08:54:07 klaatu kernel: [85703.535692]   .next_balance                  : 4316.339401
Jun 20 08:54:07 klaatu kernel: [85703.535695]   .curr->pid                     : 0
Jun 20 08:54:07 klaatu kernel: [85703.535699]   .clock                         : 85703534.602720
Jun 20 08:54:07 klaatu kernel: [85703.535703]   .cpu_load[0]                   : 617

Then it hits help again:
Jun 20 08:54:08 klaatu kernel: [85704.272930] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:08 klaatu kernel: [85704.272937] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:08 klaatu kernel: [85704.296510] atkbd serio2: Unknown key pressed (raw set 2, code 0x18 on isa0060/serio2).
Jun 20 08:54:08 klaatu kernel: [85704.296518] atkbd serio2: Use 'setkeycodes 18 <keycode>' to make it known.
Jun 20 08:54:08 klaatu kernel: [85704.297859] SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) thaw-filesystems(J) saK show-backtrace-all-active-cpus(L) show-memory-usage(M) nice-all-RT-tasks(N) powerOff show-registers(P) show-all-timers(Q) unRaw Sync show-task-states(T) Unmount show-blocked-tasks(W) dump-ftrace-buffer(Z) 
Jun 20 08:54:08 klaatu kernel: [85704.301511] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:08 klaatu kernel: [85704.301519] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:08 klaatu kernel: [85704.321414] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:08 klaatu kernel: [85704.321422] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.

It hits Help several more times before things take a turn for the interesting:

Jun 20 08:54:12 klaatu kernel: [85708.455038] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:12 klaatu kernel: [85708.455046] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:12 klaatu kernel: [85708.474757] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:12 klaatu kernel: [85708.474765] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:12 klaatu kernel: [85708.476031] SysRq : Manual OOM execution
Jun 20 08:54:12 klaatu kernel: [85708.476557] kworker/0:1 invoked oom-killer: gfp_mask=0xd0, order=0, oom_adj=0, oom_score_adj=0
Jun 20 08:54:12 klaatu kernel: [85708.476564] kworker/0:1 cpuset=/ mems_allowed=0
Jun 20 08:54:12 klaatu kernel: [85708.476571] Pid: 10320, comm: kworker/0:1 Tainted: P           O 3.2.0-25-generic #40-Ubuntu
Jun 20 08:54:12 klaatu kernel: [85708.476576] Call Trace:
Jun 20 08:54:12 klaatu kernel: [85708.476589]  [<ffffffff810bffad>] ? cpuset_print_task_mems_allowed+0x9d/0xb0
Jun 20 08:54:12 klaatu kernel: [85708.476601]  [<ffffffff8111ad91>] dump_header+0x91/0xe0
Jun 20 08:54:12 klaatu kernel: [85708.476607]  [<ffffffff8111b115>] oom_kill_process+0x85/0xb0
Jun 20 08:54:12 klaatu kernel: [85708.476613]  [<ffffffff8111b4ba>] out_of_memory+0xfa/0x220
Jun 20 08:54:12 klaatu kernel: [85708.476623]  [<ffffffff813c5ec0>] ? sysrq_handle_term+0x20/0x20
Jun 20 08:54:12 klaatu kernel: [85708.476629]  [<ffffffff813c5ee5>] moom_callback+0x25/0x30
Jun 20 08:54:12 klaatu kernel: [85708.476638]  [<ffffffff81084f9a>] process_one_work+0x11a/0x480
Jun 20 08:54:12 klaatu kernel: [85708.476646]  [<ffffffff81085d44>] worker_thread+0x164/0x370
Jun 20 08:54:12 klaatu kernel: [85708.476654]  [<ffffffff81085be0>] ? manage_workers.isra.29+0x130/0x130
Jun 20 08:54:12 klaatu kernel: [85708.476661]  [<ffffffff8108a59c>] kthread+0x8c/0xa0
Jun 20 08:54:12 klaatu kernel: [85708.476671]  [<ffffffff81667db4>] kernel_thread_helper+0x4/0x10
Jun 20 08:54:12 klaatu kernel: [85708.476678]  [<ffffffff8108a510>] ? flush_kthread_worker+0xa0/0xa0
Jun 20 08:54:12 klaatu kernel: [85708.476685]  [<ffffffff81667db0>] ? gs_change+0x13/0x13

Yes, the problem with atkbd spitting out random keypresses actually triggered a manual OOM Killer... and it gets better:

Jun 20 08:54:13 klaatu kernel: [85709.272960] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:13 klaatu kernel: [85709.285061] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:13 klaatu kernel: [85709.285069] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:13 klaatu kernel: [85709.286069] SysRq : Terminate All Tasks
Jun 20 08:54:13 klaatu kernel: [85709.286615] init: tty5 main process (1288) killed by TERM signal
Jun 20 08:54:13 klaatu kernel: [85709.286675] init: tty5 main process ended, respawning
Jun 20 08:54:13 klaatu kernel: [85709.287125] atkbd serio2: Unknown key pressed (raw set 2, code 0x0 on isa0060/serio2).
Jun 20 08:54:13 klaatu kernel: [85709.287131] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:13 klaatu kernel: [85709.335915] atkbd serio2: Unknown key pressed (raw set 2, code 0x18 on isa0060/serio2).

It triggered TermAllTasks via SysRq before finally hitting the combination of death:
Jun 20 08:54:15 klaatu kernel: [85711.141511] atkbd serio2: Use 'setkeycodes 00 <keycode>' to make it known.
Jun 20 08:54:15 klaatu kernel: [85711.160283] atkbd serio2: Unknown key pressed (raw set 2, code 0x8 on isa0060/serio2).
Jun 20 08:54:15 klaatu kernel: [85711.160291] atkbd serio2: Use 'setkeycodes 08 <keycode>' to make it known.
Jun 20 08:54:15 klaatu kernel: [85711.161727] SysRq : Emergency Thaw of all frozen filesystems
Jun 20 08:54:15 klaatu kernel: [85711.161745] Emergency Thaw on sda6
Jun 20 08:54:15 klaatu kernel: [85711.161749] Emergency Thaw on sda6
Jun 20 08:54:15 klaatu kernel: [85711.161752] Emergency Thaw on sda6
Jun 20 08:54:15 klaatu kernel: [85711.161755] Emergency Thaw on sda6
Jun 20 08:54:15 klaatu kernel: [85711.161758] Emergency Thaw on sda6
Jun 20 08:54:15 klaatu kernel: [85711.161765] Emergency Thaw on sda6
Jun 20 08:54:15 klaatu kernel: [85711.161767] Emergency Thaw on sda6

At this point, the Emergency Thaw message flood commenced and my system ground to a halt and had to be power cycled to restore.

I have tried all the Precise kernels, I have tried the Upstream kernel.  This has been an issue on ALL precise kernels thus far, and has not happened at all on the Upstream kernel.  I ran the upstream for 72 hours and did not see a single atkbd message appear in the logs.  On any Precise kernel, it happens so much I need to reboot at least once, sometimes twice per day.